Joe Petrosinelli has an active civil and criminal litigation practice. He has tried numerous cases in federal and state courts. In 2003, he was selected by The American Lawyer as one of the "top 45 under 45", a group of the highest performing members of the private bar under the age of 45. Mr. Petrosinelli is a member of the firm's Executive Committee.

Mr. Petrosinelli's civil practice focuses on products liability and mass tort/class action litigation, in which he has represented manufacturers of various chemicals, pharmaceuticals, equipment, and other products in cases across the country and internationally. He has also litigated a wide variety of other types of civil matters, including antitrust, securities, professional liability, and other cases. Mr. Petrosinelli is an Adjunct Professor of Law at Georgetown University Law Center, where he teaches trial practice.

Mr. Petrosinelli has extensive experience in criminal litigation of all types, including federal grand jury practice and trial and appellate work in federal and state courts. He has represented both individuals and large corporations in matters involving allegations of mail and wire fraud, money laundering, false claims, false statements, and antitrust violations, among other things. He and two of his partners successfully represented the petitioner before the U.S. Supreme Court in Cleveland v. United States, 531 U.S. 12 (2000), a leading case on the interpretation of the federal mail and wire fraud statutes.

Mr. Petrosinelli has also been involved in the firm's sports law practice. He is a certified agent of the National Basketball Players Association, and has represented athletes, professional clubs, and club executives in litigation and contract matters.