We describe our experience using the nocturnal penile tumescence and rigidity monitor (NPTR) in 181 impotent patients referred to the specialized evaluation service in our Family Medicine Center, and review the literature. The 181 patients were referred to the center during 18 months. Their mean age was 53.5 +/- 9.45 years (range 26-76) and 92% were married; about a quarter (26.8%) suffered from impotence for 4-10 years. They were referred by urologists (54.7%), psychiatrists (24.3%), and general practitioners (13.8%). About a third had a normal rigidity, more than half had a normal base tumescence, but only a quarter had normal tip tumescence. Abnormal rigidity and tumescence was significantly associated with diabetes but not with hypertension. We conclude that family physicians have to be actively involved in and responsible for the diagnosis and treatment of impotent patients. Reading and interpreting NPTR is a simple as reading an electrocardiogram and can easily be performed in a primary care setting.