Daniel B. Ravicher, Partner


  • University of Virginia, J.D. 2000
  • University of South Florida, B.S.C.E., 1997


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  • Florida
  • New York
  • Supreme Court Of The United States
  • U.S. Court of Appeals for the Federal Circuit
  • U.S. Court of Appeals for the 2nd Circuit
  • U.S. Court of Appeals for the 11th Circuit
  • U.S. District Court for the Southern District of New York
  • U.S. District Court for the Eastern District of New York
  • U.S. District Court for the Southern District of Florida
  • U.S. District Court for the Middle District of Florida
  • U.S. Patent and Trademark Office


Daniel B. Ravicher represents clients in business and technology related litigation and transactions, which he’s done since the dotcom boom.

Dan’s litigation experience includes representing intellectual property rights holders and accused infringers in cases across the country involving pharmaceuticals, biotechnology, medical devices, semiconductors, telecommunications, software, consumer electronics, and other technologies. He won the 2013 Supreme Court case that held human genes cannot be patented, successfully protected organic farmers from Monsanto’s patents on genetically modified seed, and defended the integrity of open source software projects. Dan has also represented both patent holders and challengers in inter partes reviews and other proceedings at the U.S. Patent & Trademark Office. In addition to intellectual property, he has litigated contract, corporate, securities, civil rights, antitrust, and administrative disputes as well. Dan has litigated in various federal and state courts and in international arbitrations.

Dan’s transactional experience includes financing, exit, and technology transactions. He has represented clients in angel, VC, M&A, and IPO transactions, negotiated sales and licenses of intellectual property, and advised on intellectual property infringement, validity, and valuation issues. A registered patent attorney, Dan has also prosecuted patents, trademarks, and copyrights for clients. In addition to being an investor in and advisor to private and public life sciences, information technology, and other companies, he also regularly consults with investment banks, hedge funds, and individual investors on legal issues that may materially affect the value of private and publicly traded companies.

Dan was twice named one of ‘The 50 Most Influential People in IP’ by Managing Intellectual Property and Appellate Lawyer of the Week by the National Law Journal. He appeared as a guest on the PBS NewsHour and has been quoted by the Wall Street Journal, the New York Times, the Financial Times, and countless other publications. He has presented at dozens of conferences and public events on issues relating to technology law, including being invited by Congress twice to be a witness on the topic of patent reform. Dan has also consulted with the United Nations and other international bodies on legal issues impacting access to essential medicines.

Professional History

Prior to Zeisler PLLC, Dan directed the Public Patent Foundation, a non-profit patent reform organization he founded with support from the Rockefeller Foundation, the Nathan Cummings Foundation, the Open Society Foundation, and the Echoing Green Foundation, among others. He was previously associated with Brobeck, Phleger & Harrison LLP, and Patterson Belknap LLP, both in New York. Dan taught Patent Law and Startup Law at the University of Miami School of Law and the Benjamin N. Cardozo School of Law.


Dan is admitted to the U.S. Supreme Court, the U.S. Courts of Appeals for the Federal, 2nd, and 11th Circuits, the U.S. District Courts for the Southern and Eastern Districts of New York and the Southern and Middle Districts of Florida, the States of New York and Florida, and the U.S. Patent and Trademark Office.


Dan received his law degree from the University of Virginia School of Law, where he was the Franklin O’Blechman Scholar of his class, a Mortimer Caplin Public Service Award recipient, and an Editor of the Virginia Journal of Law and Technology.  He received his bachelors degree in materials science magna cum laude with University Honors from the University of South Florida.