Private Investigation and Process Serving in Beaverton, Portland and all other locations in Oregon and SW Washington.

Our office is normally staffed between 8am & 5pm M-F PST.   If we miss your call, please leave a message.   We check messages often when we are working in the field.   You may also send us an email.

Mailing Address:  4550 SW Betts #157  Beaverton, OR 97005

Email Address:

Phone: 503-643-4274

Office Address: Click Here

Fax #: Click Here


About Us

Mark Ososke, licensed investigator and owner, has been conducting private investigations and process serving in Oregon since 1988.  Ten years later, in 1998, the State of Oregon began licensing and regulating Private Investigators.  Each member of Mark’s staff has a minimum of 10 years’ experience.  When you care about the quality of your work, your clients get the best results.  Our results and personalized customer service are what our clients tell us they respect and appreciate about us most.  On a personal note, Mark was raised in Portland Oregon.  Is married and the father of 2 children.  Mark enjoys spending time with his family and friends as well as mountain biking, skiing, camping, playing basketball, and watching Trail Blazer & Seahawks games.


I want your feedback. If you have a question, concern or want to talk about your experience working together, then I would like to hear from you.  Please call or email me directly.

Thank you
Mark Ososke

Our Staff: Karen, Joe, Tim, Beth, Heike, Douglas, Tor, Linda.

We carry 2 million of E & O Insurance to protect our Clients.

Kudos – Customer Testimonials

If you are happy with our service please do a review and tell Google.   The following are nice emails we have received or that have been posted by others.

“In my experiences with Mark over the last 20 years, I have found him to show the highest degree of professionalism, ethical standards, skill and knowledge in the area of Process Service and Investigations. I highly recommend Mark at PI Services.”
Christopher Pfeiffer – Process Server

“I have used Mark exclusively for the past 17 years or so. I have used him both in the Metro area and on the North Coast in association with my Astoria office. Mark has found and served some of the most difficult people I have had to serve. He has found addresses on folks I thought would never be found. My suggestion would be to call Mark.”  Posted on Oregon Trial Lawyers Association-2010
Martin Alvey – Attorney  Martin Alvey PC

“I have used PI for 13 years, they have been able to track down and serve even the most elusive and difficult defendants.  Also great at locating people and their rates are very reasonable.”  Posted on OTLA-2010
Kenneth Dobson- Attorney  Chenoweth Law Group

“I have always received excellent service from PI Services. Mark, outstanding work, as always. Thanks.”  Posted on OTLA-2010
Alex Golubitsky – Attorney  Case & Dusterhoff LLP

“Everything gets taken care of, that’s why we work with you Mark, you are the best!” Sent via Email
Leslie L. Van Dyk – Paralegal   Tarlow Naito & Summers LLP

“Like I’ve said before, you are the best, Mark “   Sent via Email
Linda Andrews – Riggs Paralegal   NW Injury Law Center

“If only you could see the smile on my face right now!  Awesome, Thanks Mark “   Sent via Email
Sheila Wagnor – Paralegal   Robert J. Miller Sr.

You guys are amazing! We honestly couldn’t be happier and are so glad we found you! 🙂 Kayla Smith, Legal Assistant to Raymond F. Thomas  @    THOMAS, COON, NEWTON & FROST

“Hi Mark!  Just wanted to thank you for your outstanding service!  I so enjoyed working with you AND I want to say THANK YOU.  You were very instrumental in helping me finish such an unpleasant task.  I will most definitely recommend you to anyone needing your service! Everything gets taken care of, that’s why we work with you Mark, you are the best!”  Sent via Email
With Appreciation, P. Harris – Client

I know most of you probably already know about what a great process server Mark Ososke is.  But I can’t help it, I just need to sing his praises again.  We have a case were the defendant has turned out to be quite difficult to locate (don’t we all just hate that).  Mark learned that the defendant had a date in traffic court, and figured he could have the guy served there.  Unfortunately, it turned out the guy paid his fine without going to court – back to square one (sigh).  Mark emailed me to report the missed chance and we discussed our deadline and budget.  My lawyer was out on vacation, and I didn’t have an immediate answer as to budget.  This was on Tuesday.  Well, my lawyer got back yesterday, and today (Thursday) I replied to Mark with our budget.  Mark shot right back that they had already found and served the guy – for half the budget!  So – yet more kudos for Mark Ososke and his team!”  Posted on OTLA-2012
Christy Brewsaugh – Paralegal  David Paul PC

Mark,  I think you guys are doing great. You are knowledgeable, quick to answer questions, and have good turnaround time.  I tell people about how great you guys are to work with whenever I get the opportunity.  Thanks for your help on these. It is really helping to push for change in the industry.  Tina Boggs – Precision Body & Paint Inc.  Beaverton, OR

My claim for Vehicle Diminished Value compensation stalled due to inaction by Allstate Insurance. My DV consultant, Auto Damage Experts, Inc., referred me to PI Services to assist in filing a claim in Small Claims Court.  The people at PI knew exactly what to do, had all the required filing forms and the PI staff was valuable in perfecting the filing. Their fee was reasonable and their process server was diligent, accomplishing service and getting the attention of the insured’s company. They followed up on my filing without prompting. All costs of the small claims filing were paid without dispute by Allstate. I would use them again in an instant and highly recommend them to anyone needing this specialized expertise.     “Mark, I went onto your website to write a referral but couldn’t locate the link to do so. Please feel free to post this to your Facebook, Yelp or your site.”   Nick, Portland, OR

Mark,  I want to thank you for the great service you performed for me in finding my friend. Even though it had been 36 years since I’d seen her and she had moved several times, including out of state, you were able to find her quickly and I might add, economically.  The rest of the story is that the reason she didn’t respond to your first attempt at contact was because at the time I was trying to find her she had experienced a significant health setback. She told me that your letter, follow up letters and her subsequent contact with me have had a positive impact on her recovery. I can’t thank you enough for finding her… and at just the right time. Your work may have actually saved a life here. Great job!  I posted a couple of reviews for you on yelp and the YP pages.  I can’t thank you enough and I will whole-heatedly recommend you and your services.   B Hughes.  – Client in TX  Sent via Email and posted on Yelp & YP Pages

I spent over a year and a half working to try and recoup money that was owed to me by a previous room mate. After not getting any responses from him or any payments, i decided to file in small claims court. Once i got the forms to fill out, I felt even more confused and frustrated then I did before. That is when i Found PI services. They took care of everything, from filling out the forms and sending it into the court. They also served the defendant for me and kept me up to date as to everything that was going on. I am now working with them and the courts to reclaim my money. I couldn’t have done this without them and I felt that they were considerate and understood where i was coming from. I would refer them to anyone that is trying to get a small claims suit taken care of. They are the best! Will D. -Portland  Found on

Mark, I just received the papers from you by mail, very professional, accurate documenting and very reasonable fee.  It was really nice and good to know you.  Hope to deal with you again if my friends or I need your help.  Wish you all the best and thank you for your help and support.  Moumen A.  – Beaverton Client Sent via Email

I feel so much better, I can’t tell you how much you have helped my stress levels with this issue!   I really truly appreciate your help and I will be using you for any future things and telling my friends about your great service.  I was very determined to get this all done today, I imaged the serving process taking an eternity, I found out he had taken the day off today and would be home all day!  I just had to get it to him it was my golden window of karma letting this be possible, and you and your company made it happen!  Just thought it would be rewarding to know how much you really helped today!  Take care,  Ashley  – Hillsboro  Client Sent via Email

Awesome…you da man!  I am going to be putting you in my “Million Dollar Rolodex” as a resource for my Clients.  Cheers ! Lawrence Beeland Realty Group  Client Sent via Email

I wanted to leave a review on you website but I did not see where I could do it. I really want to say thank you Mark. You were so great during a difficult time. You were persistent in serving my husband with divorce papers and you did it very quickly. I really appreciate your patience and willingness to keep trying to get my husband to come to the door. Mark is really great and I would recommend his services to anyone.  Thanks again, Tami in Beaverton  Client sent via email.

Hi Mark,  Thank you again for everything – you are not only excellent at what you do but you have an incredibly kind soul. Juli-Lake Oswego  Client sent via email.

You guys are the best! I am so pleased with the help and support provided. You saved me a lot of headache, time and trouble. I can’t remember how I found you, but you really helped me out a lot!!  Carla (Realtor in Portland)  Client sent via email.

I just wanted to thank you and PI Services for getting the garnishment completed & served.  We have received our first payment and even though the balance due was a small amount, we are happy that this account is being cleared.  Thank you again!  Carol Taylor-J D L Development Inc.  Client sent via email.

Mark and his team are fantastic. I found myself Backed into a corner, over matched and unprepared when my uncontested divorce suddenly became contested. I needed information and I needed it fast. Mark and Heike were all over it.They got me everything I needed and more than I expected faster than I imagined. I had everything I needed and was prepared to do battle. Though it was no fault of theirs, I got my ass kicked anyway. But what else did I expect? I’m a guy, this is Oregon and she’s the devil. It was gonna happen anyway. Seriously though, they are great people, eager to help and even fun to work with. My next divorce? I’m going right back to them. Only next time, I’ll go before it’s too late Ron S.   Client sent via email.
I had a great experience working with Mark and his team. Let’s be honest: by the time you’re hiring for investigation services, chances are you’re going through a stressful situation with an uncertain outcome. While nobody can guarantee anything, what Mark does provide is:
1) An incredibly high degree of responsiveness and transparency to the status of how your ‘issue’ is progressing .
2) Earning your trust (key, in any high-stakes situation)
3) A willingness to go above and beyond.
4) Getting sh*t done.
I had PI Services perform work related to researching and serving somebody who had ‘skipped town’: I was extremely satisfied with my outcome (along with their approach) and would easily use them again.  Mr. V.C.,  Client from Seattle, WA posted this on Yelp
Hello Mark,  Thank you very much for getting Seterus to fill out as per the instructions. I greatly appreciate your help and assistance in this matter.  You made my day.  Sincerely,  R. Hernandez, Florida  May 2016

Thank you, Mark.   Again, thank you for your help.  It has resulted in an enormous revelation that helps considerably in my case and strategy for a fair and just resolution.  It also resolves my confusion about my relationship with my husband. While the outcome is not pleasant, there is comfort in knowing the genesis of the problems and issues.   Christine K.  Lake Oswego

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