It has been found that polycystic kidney (ADPKD) is often associated with gout. On the other hand, there are reports describing that the hyperuricemia (HU) seen in ADPKD corresponds to a reduction in renal function. We investigated the uric acid metabolism in 44 patients with ADPKD (age, 50 +/- 12.8 years; CCR, 50.5 +/- 41.1 ml/min) at our hospital. From among these 44 patients, 14 with a CCR of 80 ml/min were selected. Their data for uric acid metabolism were compared against those from the previous year's studies on various disease types (114 normal subjects, 70 with membranous nephropathy, 175 with IgA nephritis, 122 with gout, 137 with asymptomatic hyperuricemia, and 42 with diabetes mellitus). Among the 44 patients with ADPKD, the serum uric acid (SUA) was 7.7 +/- 1.9 mg/dl and HU affected 28 (63.6%). The incidence of gouty arthritis was also high (6 patients, 13.6%), revealing a positive correlation between SUA and CCR. Compared with membranous nephropathy and IgA nephritis, ADPKD exhibited an accentuated increase in SUA associated with a reduction in CCR. It is believed that this represents a factor for a high incidence of complications of hyperuricemia and gouty arthritis in ADPKD in contrast to other diseases. However, no increase in the production of uric acid was noted in ADPKD.