R. Brent Wisner

R. Brent Wisner

recognized lawyers icon Recognized in Best Lawyers since 2021
Awarded Practice Areas
Consumer Protection Law Personal Injury Litigation - Plaintiffs Product Liability Litigation - Plaintiffs
Works at
Wisner Baum PC

6 Best Lawyers awards

Wisner Baum PC logo

Biography

Brent Wisner is the managing partner and lead trial attorney at Wisner Baum, where he focuses his practice on complex, high-stakes litigation, including complex and multidistrict litigation, class actions, toxic torts, and products liability cases. Recognized as one of America’s 50 Most Influential Trial Lawyers by Trial Lawyer Magazine, Brent has built a reputation for taking on large corporations in high-stakes litigation and winning significant verdicts and settlements for his clients.

Over the last several years, Brent has served on the plaintiff’s leadership for multiple mass torts, earned jury verdicts worth a combined $2.427 billion, and helped negotiate settlements in excess of $1 billion—all before the age of 40. He is currently the youngest attorney in American history to win a multi-billion-dollar jury verdict, which he achieved with a $2 billion Roundup cancer verdict against Monsanto on behalf of the Pilliods.

While success in the courtroom is often measured exclusively by dollars and cents, Brent’s legal work has led to changes in business practices that will protect people and the environment for generations. Hundreds of media publications across the globe have asked for his perspective on a variety of pressing legal issues.

Considered one of the most important business publications, the Financial Times published a feature article on Brent, following a ruling in his favor that greenlights over 70,000 Zantac cases. The paper stated Wisner is “now seeking another Big Pharma scalp: UK drugmaker GSK. The company lost £7bn in value on Monday after a ruling by a Delaware judge last week left it exposed to US jury trials over its allegedly carcinogenic heartburn treatment Zantac.”

His team has obtained class certification for the first non-settlement national Racketeer Influenced and Corrupt Organizations Act (RICO) class action lawsuit against Big Pharma. The RICO case is against Takeda Pharmaceutical Company and Eli Lilly and Company. The class action alleges both drug companies conspired to conceal the bladder cancer risk associated with the diabetes drug, Actos, because they knew that adding a cancer warning label would harm sales. Experts say the damages total under RICO with trebled damages could reach $7 billion or more.

Wisner Baum is also leading several mass tort litigations that will see their first trials in the country. These include the Zantac cancer litigation in California, in which he serves as co-lead counsel for the Ranitidine Product Cases JCCP 5150 where at least 5,000 cases are filed. Brent also serves as Plaintiffs’ Co-Lead National Counsel for the Delaware Zantac litigation where more than 75,000 plaintiffs have filed lawsuits. Wisner Baum will also likely try the first of its kind toxic baby food lawsuit in California in 2024 and the first Gardasil HPV vaccine injury lawsuit against Merck.

Brent believes that being a trial lawyer is more than just securing large verdicts, it is also about using the law to affect real change and obtaining justice for your clients.

A perfect example of using the law to make the world a better place is his firm’s release of the Monsanto Papers. By releasing unsealed key internal Monsanto documents to the EU, US DOJ and California EPA, the truth was revealed about Monsanto’s rampant corporate malfeasance to manipulate the science and collude with the EPA to hide the health risks associated with using Roundup. These documents helped change the narrative across the globe surrounding the weedkiller.

Works at
Wisner Baum PC

6 Best Lawyers awards

Wisner Baum PC logo

Locations

Languages

  • English
  • French
  • Spanish

Education

  • Georgetown University, J.D., graduated 2010
  • Georgetown University, M.P.P., graduated 2010
  • University of California - Los Angeles, B.A., graduated 2005

Bar Admissions

  • California, The State Bar of California, 2011
  • District of Columbia, The District of Columbia Bar, 2021
  • Pennsylvania, Pennsylvania Bar Association, 2024

Court Admissions

  • District of Columbia Court of Appeals, 2021
  • U.S. Court of Appeals, Eleventh Circuit, 2020
  • U.S. Court of Appeals, First Circuit, 2013
  • U.S. Court of Appeals, Ninth Circuit, 2014
  • U.S. Court of Appeals, Seventh Circuit, 2014
  • U.S. District Court, Central District of California, 2013
  • U.S. District Court, District of Colorado, 2016
  • U.S. District Court, Eastern District of California, 2013
  • U.S. District Court, Northern District of California, 2012
  • U.S. District Court, Northern District of Illinois, 2017
  • U.S. District Court, Southern District of California, 2013
  • U.S. District Court, Southern District of Indiana, 2015
  • U.S. District Court, Western District of Wisconsin, 2016
  • U.S. Supreme Court, 2014

Affiliations

  • American Association for Justice - Leader’s Forum - Champion; Class Action Section; Environmental and Toxic Torts Section; Pharmaceutical and Medical Device Section; Herbicides and Pesticides Litigation Group; Class Action Litigation Group; Zantac Litigation Group (Co-Chair)
  • Consumer Attorneys of California - President’s Club Benefactor - Sustaining Member
  • Consumer Attorneys Association of Los Angeles - Member
  • Federal Bar Association - Federal Litigation Section; Younger Lawyer Division
  • Litigation Counsel of America - Diversity Law Institute
  • Litigation Counsel of America - Fellow
  • Litigation Counsel of America - Trial Lawyer Institute
  • San Francisco Trial Lawyers Association - Member

Federal Clerkships

  • United States Court of Federal Claims
  • United States District Court

Client Testimonials

Brent is one of the nicest people you’ll ever meet. He is the best trial attorney in the industry. Mr. Wisner has won billions of dollars in some of the most famous cases. His skills are unmatched by any other professional attorney. Everyone that has heard about him agrees that he is the very best. I am blessed to have him on my side. I am very privileged he is representing me.

Craig Groth

Awards & Focus

Recognized in The Best Lawyers in America® 2026 for work in:
  • Consumer Protection Law
  • Personal Injury Litigation - Plaintiffs
  • Product Liability Litigation - Plaintiffs
Additional Areas of Practice:
  • Mass Tort Litigation / Class Actions - Plaintiffs
Awards:

Additional Information

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Case History

Cases
  • Baby Food Products Liability Litigation, MDL No. 3101 (U.S. District Court, Northern District of San Francisco)
Co-Lead Plaintiff’s Counsel
  • Zantac (Ranitidine) Litigation, Superior Court of the State of Delaware, Case No. N22C-09-101
Co-Lead Plaintiffs’ Trial Counsel
  • Ranitidine Product Cases, also known as the Ranitidine (Zantac) Judicial Council Coordinated Proceedings (JCCP 5150), California Superior Court for the County of Alameda, California
Co-Lead Plaintiffs’ Liaison Counsel
  • In re: Zantac/Ranitidine NDMA Litigation, MDL No. 2924 (U.S. District Court, Southern District of Florida)
Member, Practices and Procedures Team
  • Pilliod et al. v. Monsanto Company
Trial Co-Lead Counsel
  • Hardeman v. Monsanto Company
Trial Counsel
  • In re: Roundup Products Liability Litigation for JCCP 4953 (Alameda County Superior Court)
Liaison Counsel to Federal MDL 2741
  • Dewayne “Lee” Johnson v. Monsanto Company
Trial Co-Lead Counsel
  • Roundup Products Cases, JCCP 4953 (Alameda County Superior Court), 2018
Plaintiffs’ Steering Committee, Administrator & Co-Lead Counsel
  • Wendy B. Dolin v. GlaxoSmithKline LLC
Trial Co-Lead Counsel
  • Cymbalta Drug Cases, JCCP 4825
Plaintiffs’ Steering Committee/Liaison Counsel
  • Hagen-Brown v. Eli Lilly
Trial Co-Lead Counsel

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