Morrison & Foerster

As of May 2026, Morrison & Foerster LLP, often called MoFo, stands as a prominent international law firm with a highly regarded patent litigation practice. Headquartered in San Francisco, the "BigLaw" firm employs over 1,000 attorneys across approximately 17 global offices. The firm consistently ranks among the top firms in the AmLaw 100 and Vault Law 100. Industry publications frequently recognize its intellectual property group with top-tier rankings; Chambers USA, for example, awarded the firm a "Band 1" ranking for Patent Litigation in California and for IP Appellate work nationwide in its 2025 guide.

Morrison & Foerster's patent litigators are known for handling complex, high-stakes disputes for major companies in the technology and life sciences sectors. Their technical expertise spans a wide range of areas including software, semiconductors, consumer electronics, data encryption, medical devices, biotechnology, and pharmaceuticals. The firm's website notes that its IP litigation team includes over 125 lawyers, many of whom hold technical degrees, allowing them to effectively litigate cutting-edge technologies. The firm maintains a balanced practice, representing both patent owners and accused infringers. Its litigators have "delivered billions of dollars in aggregate damages on behalf of patent owners and have defended nearly 1,000 patent cases on behalf of patent challengers," according to the firm. This is more representative than the single plaintiff-side case in the provided data (Neomedia Technologies, Inc. v. Symbol Technologies, Inc.).

The firm has secured significant public victories for its clients in district courts, at the Federal Circuit, and before the Patent Trial and Appeal Board (PTAB). Recent notable outcomes include securing a complete defense verdict for Epic Games in a patent infringement case concerning virtual concerts in its Fortnite game, obtaining a summary judgment victory for Palo Alto Networks in a long-running patent dispute, and achieving a significant confidential settlement for Virtru Corp. in a data encryption patent case against Microsoft just days before trial. The firm also represented Avadel Pharmaceuticals in securing a $90 million payment and a global patent license from Jazz Pharmaceuticals.

Morrison & Foerster has a robust practice before the PTAB, handling inter partes review (IPR) and other post-grant proceedings, as well as matters before the International Trade Commission (ITC). Chambers notes the firm has an "excellent reputation for its handling of IPRs." The practice is led by a deep bench of seasoned trial lawyers. Key partners frequently cited in industry rankings and major cases include Daralyn Durie, a nationally recognized trial lawyer; Bita Rahebi, co-chair of the firm's Global IP Litigation Group; and Richard Hung, co-chair of the firm's Global Litigation Department.