The study concerns 105 cases of dominant polycystic kidney disease. Affected relatives were observed in 65% of patients. The clinical features that leads to diagnosis were lumbar pain in 37.5% of cases, renal failure in 24.6% of cases and hypertension in 15.1% of cases. Hypertension was observed in 46.7% of cases and it seems that its onset is independent of chronic renal failure. Its frequency is of 55.1% when only kidneys were affected and of 21.4% when the liver was affected too. The progression of chronic renal failure is influenced by hypertension.