Diane B. Roldán

Diane is an associate in the Complex Litigation and Health Care practices.
Diane B. Roldán, Associate, Los Angeles at Arent Fox

Diane helps businesses, particularly hospitals and midsize companies, resolve disputes through litigation, arbitration, and administrative hearings. She counsels clients at every stage of litigation, from filing or answering the initial complaint to the winning jury verdict or arbitration decision.

Diane specializes in the health care sector. She regularly represents hospitals, medical staffs, residency programs, and major health care systems throughout California in complex litigation, peer review proceedings, and administrative hearings. She is a trusted advisor to clients on regulatory reporting, credentialing procedures, and fair hearing rights.

Diane also represents midsize businesses, national corporations, and investors in state and federal court, as well as numerous forms of domestic and international arbitrations. In 2017, Diane won one of the top 25 breach of contract verdicts in California for a state court jury trial.

Prior to joining Arent Fox, Diane clerked for the Honorable John R. Fisher of the DC Court of Appeals in Washington, DC.  Diane received her law degree from Stanford Law School, where she was named a Stanford Public Interest Fellow.

Health Care Litigation & Peer Review

  • Diane currently represents hospitals throughout California in multiple medical staffs in peer review hearings involving summary suspensions, restrictions, and termination recommendations.
  • Diane is counsel to a large California health system in civil litigation involving a physician summary suspension, alleged whistleblower retaliation, and the Anti-SLAPP statute.  The case is currently pending before the California Supreme Court.
  • In 2018, Diane represented the California Hospital Association as an amicus curiae to the California Court of Appeal on the issue of peer review hearing officer neutrality.
  • Diane defends a leading Southern California hospital’s residency program against whistleblower retaliation, sexual harassment, and breach of contract claims brought by a former resident.

Health Care Provider Counseling

  • Diane regularly advises clients on regulatory reporting requirements, including for the National Practitioner Data Bank (NPDB) and Medical Board of California Section 805 reports.
  • Diane supports hospitals and medical staffs during California Medical Board investigations, including responding to subpoenas and witness interview requests.
  • Diane has extensive experience advising medical staffs on credentialing standards for new applicants and reappointments.
  • Diane also assists two hospitals in revising their medical staff bylaws to conform with modern best practices.

Complex Civil Litigation

  • Diane recently won a complete jury trial victory in California state court for a client whose former employee stole millions of dollars’ worth of trade secrets before joining a major competitor in China.  This case was one of the Top 25 breach of contract verdicts in California in 2017.
  • Diane represented a footwear company against state and federal claims alleging trade secret theft, patent infringement, breach of contract, and unfair competition.
  • Diane defended Chevron U.S.A. Inc. and Chevron Corp., in connection with claims filed by the City of Richmond related to a 2012 refinery fire in Richmond, California. Prior to trial, the case settled for a nominal amount in 2018.
  • Diane successfully dismissed all federal claims brought against her client in at the outset of the case for lack of personal jurisdiction and improper venue.
  • Diane defended a multinational energy company in an AAA arbitration with a supplier alleging breach of contract.
  • Diane represented a California cannabis company against claims of breach of contract, fraud, and unjust enrichment.

International Arbitration

  • Diane represented a sovereign nation in two international arbitrations under UNCITRAL rules and a state-to-state arbitration at the Permanent Court of Arbitration in The Hague. 
  • Diane defended an international investor alleging expropriation under NAFTA and a Spanish distributor in an ICC arbitration with its U.S.-based supplier.    
  • Diane represented a telecommunications company alleging expropriation of assets by sovereign state under NAFTA.
  • Diane successfully convinced the US Treasury Department’s Office of Foreign Assets Control’s (OFAC) to remove a Zimbabwean corporation from the Specially Designated Nationals (SDN) and Blocked Persons list.
  • Diane won a complete victory for a pro bono client, when the United Nations Mechanism for International Criminal Tribunals (UN MICT) withdrew its allegation of contempt against a film production company screening its award-winning documentary chronicling the first-ever prosecution of rape as a crime of war.


Diane's recent publications and presentations include:

  • “Teaming With Your Lawyers to Avoid Lawsuits: Strategies for Medical Staffs and Hospitals,” Mar. 1, 2019.
  • “Is It Reportable? HRSA Updates NPDB Guidebook for the First Time in Three Years,” Nov. 8, 2018.
  • “Arbitration in California,” Delos Dispute Resolution’s Guide to Arbitration Places, 2018.
  • “Whistleblower Lawsuits and Peer Review,” Medical Staff Leaders and the Law 2018: Costa Mesa, February 2018.
  • “Making the Most of Prejudgment Writs of Attachment,” Los Angeles Lawyer, September 2017.