To develop a profile of nonazotemic polycystic kidney disease as it occurs in families, we identified and studied 164 persons with autosomal-dominant polycystic kidney disease, 81 persons suspected of having the disease, and 250 family members without the disease. Because symptoms were absent in 32% of patients with the disease but present in 30% of persons without the disease, symptoms are not reliable in screening for the disease. Hypertension and palpable kidneys and liver were significantly commoner in patients with the disease, but systolic murmur unrelated to hypertension (10.5%) and peripheral edema (9.3%) also were common. Normal laboratory values do not exclude the diagnosis of polycystic kidney disease. Ultrasonography appears to be more sensitive than excretory urography in detecting the disease and also can detect hepatic cysts. Berry aneurysms can occur and are an important cause of mortality and morbidity. The relation of renal cysts to signs, symptoms and renal function is discussed.