Geoff Yost


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Geoff brings more than 21 years of experience to his practice, which focuses on high-technology patent, antitrust, and commercial litigation, as well as environmental litigation, including contamination disputes, toxics issues, government enforcement, and water and other natural resources disputes. He is also a member both of the firm’s Intellectual Property and Technology practice and its Energy, Natural Resources, and Environment practice and has extensive experience with patent litigation, environmental citizen suits, Proposition 65, and cleanup cost recovery actions.

Geoff’s clients span a wide range of industries and include semiconductor manufacturers, consumer electronics makers, Electronic Design Automation specialists, transportation companies, real estate trusts and trustees, banks, retailers, and consumer products manufacturers.



Bar Admissions

  • California

Court Admissions

  • U.S. District Court, Eastern, Northern, and Southern Districts of California
  • U.S. Court of Appeals, Ninth Circuit
  • U.S. Court of Federal Claims


  • Santa Clara University School of Law, J.D., 1991: cum laude; Emery Scholar
  • University of California at Berkeley, B.A., 1987

Professional Activities


  • California Supreme Court (1990)


  • San Francisco Bar Association

Adjunct Professor

  • University of California, Hastings College of Law (1998)

Editorial Board

  • Environmental Liability, Enforcement and Penalties Reporter (2000-2008)
  • Represented a large, multinational semiconductor manufacturer in multiple patent and antitrust actions against a high-profile computer memory interface technology firm
  • Helped to try patent infringement case and obtained a favorable jury verdict and a permanent injunction on behalf of major EDA company against its primary competitor
  • Defended a price fixing antitrust suit against major semiconductor manufacturer ultimately resolved by settlement
  • Defended and settled state hazardous waste handling enforcement action against a major transportation company
  • Defending a large, multinational consumer electronics manufacturer in patent litigation