Diane Fenner


P: 215-557-0099F: 215-557-0673



Diane Fenner graduated from the University of Pennsylvania Law School in 1983, and received her Bachelor of Arts degree with honors from Barnard College in 1973. Diane also has a Ph.D. in social psychology from the Graduate School of Arts and Sciences at Columbia University, where she specialized in the intersection between law and psychology, and was involved in jury selection as well as mock jury and focus group work in cases including the Kent State trial and the MCI v. AT&T litigation.

Diane has been practicing law since 1983, and has an AV rating from her colleagues, as determined by Martindale-Hubbell. After 4 years at the prestigious Philadelphia-based defense firm of Pepper Hamilton, Diane switched to a practice exclusively devoted to the representation of injured individuals. As such, she has practiced in various areas of personal injury, including medical malpractice, automobile accidents, premises liability, product liability, and workers’ compensation, and has lectured for the American Association of Justice and the Philadelphia Bar Association.

At the present time, Diane is concentrating her law practice in the field of pharmaceutical litigation, where she specializes in the representation of people injured as a result of harmful drugs and medical devices. For the past 15 years, Diane has co-authored the chapter in AAJ’s Litigating Tort Cases entitled “Drugs and Medical Devices,” and was involved extensively in Hormone Therapy (Prempro), Stadol, and Vioxx litigation. Because of her background as a Ph.D. social psychologist, Diane is particularly interested in the marketing aspects of pharmaceutical litigation, as well as settlement negotiation and trial strategy issues.

Diane is a member of the American Association for Justice, the Pennsylvania Association for Justice, and the Philadelphia Bar Association. She is admitted to the Supreme Court of Pennsylvania and the United States District Court for the Eastern District of Pennsylvania.

On a personal note, Diane and her husband, Dr. David Zwillenberg, have five children and many adored grandchildren. Diane has been practicing full time since graduating from law school, and recently moved back to Philadelphia after raising her children in the suburbs. In her spare time, Diane is involved in various community activities, the most significant of which is Kohelet Yeshiva. Kohelet is the only K-12 Modern Orthodox Jewish day school in the greater Philadelphia area, and Diane has been the president of the Board of Directors of the school for the past 4 years. Diane is also a trained hot line volunteer for domestic violence prevention centers.


  • University of Pennsylvania Law School, J.D. (1983)
  • Columbia University, Ph.D., Social Psychology
  • Barnard College, B.A., with honors (1973)