Gerstenhaber married Ruth Priscilla Zager on June 3, 1956, in the Spanish and Portuguese Synagogue in New York City. They lived in Merion Station, Pennsylvania, and Haverford, Pennsylvania, and had three children: Jeremy M. Gerstenhaber, David Ezra Gerstenhaber (now founder, president, and portfolio manager at Argonaut Management), and Rachel Rebecca Stern (now general counsel and head of strategic resources of FactSet). His son David, a hedge fund manager and Tiger Management alumnus, is married to financier Steven Posner 's daughter Kelly.