Skip to content Brian J. Mooney


Walnut Creek
100 Pringle Avenue
Suite 300
Walnut Creek, CA 94596


J.D., University of California, Los Angeles

B.A., honors, Political Science, University of California, Davis


AV® Preeminent™,

Litigation Counsel of America, Fellow

Best Lawyers in America® distinction in Product Liability Litigation - Defendants (2019-2024)

Super Lawyers® distinction in Personal Injury Defense: Products; Business Litigation; Class Action/Mass Torts; Bankruptcy & Creditor/Debtor Rights (2005-2020)

Who’s Who Legal California: Product Liability Defense Lawyers, “…chairs the firm’s drug and medical device group. Considered a leading figure, both in litigation and regulatory matters... ”

2010 Irish Legal 100

Who's Who in the World, America and American Law (2009-2012)

Who's Who among Executives and Professionals (2010)


Brian Mooney is a Senior Partner at GRSM with extensive experience in complex civil litigation and sophisticated commercial transactions. His clients are both start-up and established companies in a broad range of industries, including pharmaceuticals, medical devices, CMBS special servicers, chemicals, banking and financial industries, real estate, manufacturers and distributors of consumer products, electronics, information technology and retail.

Brian is the Chair of the National Drug and Medical Device Practice at GRSM and regularly serves as national product liability group defense counsel for companies in both single action and mass tort litigation. In this national capacity, he is responsible for developing and coordinating national litigation strategies as well as the defense of the individual actions, including trial. Examples of Brian’s product defense work has included a variety of products, including vascular, ocular, orthopedic and oral devices and an equally wide variety of pharmaceuticals and supplements. Recent experience includes a defense verdict in San Francisco Superior Court on behalf of the manufacturer of an antiepileptic drug, and successful arguments on an issue of first impression in the State of Kansas at the trial court level, the appellate court level, and before the Kansas Supreme Court. Brian also provides pre-litigation counseling and claim investigation services.

Brian’s commercial transactions and business litigation clients include both privately-held businesses and publicly-traded national and global corporations. His practice emphasizes the negotiation, preparation and resolution of disputes involving a broad range of business-to-business transactions, including contracts to provide consumer goods and services, purchases and sales of assets, and consumer product litigation. He also has extensive experience in bankruptcy, creditors’ rights, restructuring, workouts and related litigation, particularly with regard to assisting master servicers and financial institutions holding and/or servicing foreclosed collateralized loan portfolios. Brian has also handled litigation involving unfair competition, fraudulent and deceptive trade practices, false advertising, intellectual property, trade secrets and breach of contract actions.


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


  • American Bar Association
  • Bar Association of San Francisco
  • Defense Research Institute, Commercial Litigation Committee and Drug & Medical Device Committee
  • Litigation Counsel of America - an invitation only trial lawyer honorary society