Chronic groin pain in athletes is often difficult to diagnose and treat. There are many anatomic structures in the inguinal and groin region that have the potential to cause pain. We report 32 cases of a previously undescribed condition in athletes of "obturator neuropathy," a fascial entrapment of the obturator nerve where it enters the thigh. This condition represents a type of groin pain in athletes that is treatable by surgical means. There is a characteristic clinical pattern of exercise-induced medial thigh pain commencing in the region of the adductor muscle origin and radiating distally along the medial thigh. Needle electromyography demonstrates denervation of the adductor muscles. Surgical neurolysis treatment provides the definitive cure of this problem, with athletes returning to competition within several weeks of treatment. The surgical findings are entrapment of the obturator nerve by a thick fascia overlying the short adductor muscle. The role of conservative treatment in the management of this condition is unknown at present.