The majority of 58 patients with adult polycystic disease of the kidneys and liver or pancreas (Potter type 3) were asymptomatic and unsuspected antemortem. Infusion nephrotomography is the method of choice for diagnosing polycystic disease of the kidneys and should be performed regardless of the findings on the standard urogram, whenever the possibility of polycystic disease exists. Carotid arteriography is not advocated for all patients with polycystic disease of the kidneys but should be considered in the young hypertensive patient with polycystic kidneys. The prognosis in patients with larger kidneys or cysts, or both conditions, is less favorable.