The relationship between hyperuricemia, gout, and autosomal dominant polycystic kidney disease (ADPKD) is not widely recognized. In an attempt to further clarify this relationship, the authors have studied 17 patients with ADPKD, 9 controls, 9 patients with proven gout and chronic renal failure, 11 patients with gout and normal renal function, and 11 patients with chronic renal failure. The mean serum uric acid concentration was higher in patients with ADPKD as a group than in controls (8.0 +/- 1.7 mg/dl vs. 6.4 +/- 1.6 mg/dl, p less than .02). Clinical gout was identified in 24% of patients with ADPKD; none of the patients with chronic renal failure of other etiologies had gout. Fractional excretion of uric acid and the activity of the enzyme hypoxanthine guanine phosphoribosyl transferase (HGPRT) were not different among the groups studied. From this study the authors conclude that ADPKD should be included among those diseases associated with hyperuricemia and gout. A partial deficiency in HGPRT or abnormal renal handling of uric acid do not appear to be responsible for the increased incidence of gout in patients with ADPKD.