Donald Sonn completed two residency programs during his six years at the Long Island Jewish Medical Center in New Hyde Park, New York. Those residency programs were in the Department of Surgery and the Department of Urology. Upon their completion in 1997, Sonn began practicing as a physician at the Urology Group of Western New England in Springfield, Massachusetts and has never left since.
Trained in minimally invasive surgery, Donald Sonn is an advocate of the statistically more effective type of surgeries. Sonn has used the da Vinci Robotic Surgical System during surgeries on patients. These types of procedures are design to benefit the patient by giving them less scarring with a small incision made for the surgery, fewer days in the hospital if any and a faster overall recovery time. Sonn uses the system for treating patients with prostate cancer, which is a common cancer in the United States.