We reviewed 5477 patients with urinary calculi who presented during the years from 1975 to 1993. During this time the percentage of calcium stones has remained at approximately 86%. However over the same period the rate of urinary calculi composed of uric acid has increased and is now about 7.2%. The number of uric acid stones has increased 3.5 times compared to 1975. 355 of 394 (90.1%) with uric acid stones are male. We believe that the increase in the numbers of patients seen with gout, hyperurisemia of a high alcohol intake.