Gregory S. Tamkin

Gregory S. Tamkin




After assessing his client’s business needs and long-term strategies, Greg maximizes the legal tools available to obtain the best results possible for his clients.

Greg has argued intellectual property disputes and commercial cases in venues all over the country, including winning international arbitrations, jury trials and appellate matters. He routinely advises clients concerning all aspects of intellectual property matters, partnership disputes, securities cases, products liability issues, real estate litigation, and general contract claims.

Greg is co-head of Dorsey’s Trial Group and serves on Dorsey’s Management Committee

Education & Admissions

University of Virginia School of Law (J.D., 1994)

Dartmouth College (A.B., 1991), cum laude


  • California
  • Colorado
  • U.S. Court of Appeals for the Ninth, Tenth and Federal Circuits
  • U.S. District Courts for Colorado
  • U.S. District Courts for the Northern, Eastern, Central and Southern Districts of California
  • U.S. District Courts for the Eastern District of Texas
  • U.S. District Court for the Northern District of Illinois


  • Spanish


Representative Litigation

  • Gadeco, LLC v. Grynberg, Won Petition on Writ of Certiorari to Colorado Supreme Court concerning trial court order requiring production of medical records of a party in a commercial dispute.
  • Leprino Foods Company v. DCI, Inc., After winning summary judgment for defendant dismissing all claims in a commercial contract and fraud case, led appellate team in securing affirmance from Tenth Circuit Court of Appeal of underlying decision.
  • Sterisil v. ProEdge Dental Products, Won summary judgment in a patent infringement case on the eve of trial and successfully navigated through resolution during appeal.
  • Solannex, Inc. v MiaSole, Inc., Represented holder of patents concerning photovoltaic technology in obtaining a confidential settlement following claim construction.
  • Hunter Douglas v. Mechoshade, Successfully defended against claim of patent infringement between competitors in electronic shade industry.
  • Visioneer, Inc. v. KeyScan, Inc., Defended document imaging company in patent infringement matter.
  • Tandberg Data Corporation v. Hewlett-Packard Company, Represented data storage technology provider against Hewlett-Packard in claims and counterclaims of patent infringement concerning seven patents through successful claim construction.
  • Xantrex Technology, Inc. v. Advanced Energy Industries, Inc., Led team that obtained preliminary injunction to prevent former vice president of engineering to move to a competitor and start up competing division with use of trade secrets.
  • Fiber Optic Designs, Inc. and Holiday Creations, Inc. v. Seasonal Specialties, LLC, Led team in bringing a preliminary judgment motion against an infringer of LED based products, successfully overturning unfavorable district court ruling on appeal at Federal Circuit.
  • Bristol Bay v. Penguin Publishing, Inc., et al., Successfully dismissed case asserted against publishing company that its advertising claims were false and caused damages leading to the production of an unsuccessful Hollywood movie. Handled the case through appeal at the Colorado Supreme Court.
  • Cooper v. NCS Pearson, Inc., Successfully defeated copyright claims related to ownership of derivative testing materials. After winning summary judgment at the trial court level, we were successful in having the Tenth Circuit affirm.
  • Central Garden & Pet Company v. Doskocil Manufacturing Company, Inc., Following a trial on the merits at the Trademark Trial and Appeals Board, obtained a verdict allowing registration of our client’s mark by proving opposer’s mark was invalid for violating provision preventing trafficking trademarks.
  • T.F.H. Publications, Inc. v. Aspen Pet Products, Inc., Following a successful claim construction hearing leading to a summary judgment in favor of our client, successfully defended claim construction at the Federal Circuit, ending the case.
  • Versata Software, Inc. v. Ameriprise Financial Services, Inc., After obtaining summary judgment preempting all asserted claims based on the Copyright Act, confidentially resolving dispute.
    Rocky Mountain Honey Smoked Fish Company v. Einstein Noah, Brought a preliminary injunction motion to prevent use of client’s trademark by competitor for same product, resulting in competitor’s ceasing to use our client’s mark.
  • Global Cooling v. EC Sagittar, B.V., Successfully defended trade secret action in which our client was accused of misappropriating trade secrets of U.S. Company.

News & Resources


"Alice v. CLS Bank" Applied Broadly by the Federal Circuit

News & Press Mentions

Dorsey & Whitney Recognized Among World’s Leading Patent Firms in IAM Patent 1000
Chambers USA 2024 Recognizes Dorsey Lawyers and Practices
Dorsey Named U.S. Firm of the Year for Trademark Prosecution (Midwest); Gregory Tamkin Named U.S. Litigator of the Year (Colorado)
Super Lawyers Recognizes Dorsey Lawyers in Denver
17 Dorsey Lawyers Recognized by Benchmark Litigation
200 Dorsey Lawyers Selected for Inclusion in 2024 Best Lawyers in America, Lawyers of the Year, and Ones to Watch
IAM Patent 1000 Recognizes 20 Dorsey Attorneys in World’s Leading Patent Professionals 2023
Dorsey Attorneys and Practices Recognized for Intellectual Property Strength by 2023 IP Stars
Chambers USA 2023 Recognizes Dorsey Lawyers and Practice in Denver
Chambers USA 2023 Recognizes Dorsey Lawyers and Practices
Super Lawyers Recognizes Five Dorsey Lawyers in Denver
Tamkin, Wechter, and Tahdooahnippah Ironburg Inventions counsel for Patent Trial
Chambers USA 2022 Recognizes Dorsey Lawyers and Practices
Super Lawyers Recognizes Five Dorsey Lawyers in Denver
18 Dorsey Lawyers Recognized by Benchmark Litigation
IAM Patent 1000 Recognizes 13 Dorsey Attorneys in World’s Leading Patent Professionals 2021
Seventeen Dorsey Attorneys Ranked as Managing Intellectual Property 2021 IP Stars
Super Lawyers Recognizes Six Dorsey Lawyers in Denver
Six Dorsey Attorneys Named to Denver’s Top Lawyers 2021 List
Benchmark Litigation Recognizes 17 Dorsey Lawyers
Managing Intellectual Property Ranks Sixteen Dorsey Attorneys as 2020 IP Stars
IAM Patent 1000 Recognizes 13 Dorsey Attorneys in World’s Leading Patent Professionals 2020
Super Lawyers Recognizes Five Dorsey Lawyers in Denver
Benchmark Litigation Recognizes 17 Dorsey Lawyers
IAM Patent 1000 Recognizes 12 Dorsey Attorneys in World’s Leading Patent Professionals 2019

Industries & Practices

International Arbitration & Litigation
  • Advertising & Marketing
  • Banking & Financial Institutions
  • Class Action Litigation
  • Commercial Litigation
  • Development & Infrastructure
  • Energy & Natural Resources
  • Food, Beverage & Agribusiness
  • Healthcare & Life Sciences
  • Intellectual Property
  • Intellectual Property Litigation
  • International Arbitration & Litigation
  • Israel
  • LegalMine Document Review Solutions
  • Mining
  • Products Liability
  • Real Estate Litigation
  • Technology
  • Technology Commerce
  • Trademark, Copyright + Advertising

Professional & Civic

Professional Achievements

  • Member, Colorado Bar Association
  • Member, California Bar Association
  • Dartmouth Association of the Rocky Mountains
  • Colorado IP Inn of Court
  • IP Owners Association
  • Colorado Lawyers Committee, Board of Directors


Chambers USA 2023Chambers 2022Chambers USA 2021  Ranked in Chambers USA 2020  Ranked in Chambers USA 2019 Leading Individual  
Chambers USA 2018 Leading Individual  Ranked in USA Chambers 2017 Leading Individual  Ranked In - USA Chambers and Partners 2016 - Leading Individual      

Ranked in Chambers USA 2015 - Leading IndividualBenchmark Ligitation 2017

  • Named one of “America’s Leading Business Lawyers” by Chambers USA (Intellectual Property), 2009-2023
  • Recognized in IAM Patent 1000 - World's Leading Patent Practitioners, 2013-2015 and 2019-2023
  • Recognized as a "Super Lawyer" for Intellectual Property Litigation by Colorado Super Lawyers, 2009-2022, 2024
  • Listed as a "Best Lawyers in America", 2017-2024
  • Recognized as a "Local Litigation Star – Colorado" by Benchmark Litigation, 2015-2019, 2021-2022, and 2024
  • Recognized as an "IP Star" by Managing Intellectual Property Handbook, 2016-2023
  • Named "Denver Lawyer of the Year" in Litigation-Patent by Best Lawyers®, 2021
  • Listed as a Top Lawyer in Denver by 5280 The Denver Magazine, 2017 and 2020-2021
  • Top Tier lawyer, recommended by The Legal 500
  • One of the Top 100 Lawyers in Colorado, 2018-2019
  • Recognized as "Trial Attorney of the Year in Colorado" by Global Law Experts, 2015
Gregory S. Tamkin