A total of 316 patients (167 men and 149 women) with autosomal dominant polycystic kidney disease was studied retrospectively by a multi-institute group. With advancing patient age renal function decreased, and blood pressure, prevalence of liver cysts and probability of end stage renal failure increased. The probability of end stage renal failure was 39% in the patients in their sixties. Regression analysis indicated that polycystic kidney disease patients could expect to lose 1.1 ml. per minute of creatinine clearance per year, reaching a level of 10 ml. per minute, a point of end stage renal failure, by the age of 72.7 years. The better prognosis in our study than that reported previously in white patients might be due to the inclusion of more asymptomatic persons and/or milder genotypic expression of polycystic kidney disease in Japan. There was no sex difference in the prevalence of liver cysts (54.6%), pancreatic cysts (7.1%), intracranial aneurysms (8.0%) and hypertension (63.6%). The occurrence of pancreatic cysts was significantly associated with liver cysts. Our study clarifies several clinical characteristics of polycystic kidney disease in Japan.