216 patients were found to have had surgery for urinary calculi In a retrospective analysis of surgical records of the two general hospitals in Kelantan over a two year period. Excluding 11 patients from Terengganu and 2 patients resident in Kelantan for less than 1 year, this amounts to an annual incidence for calculus surgery of 10 per 100,000 residents per year. Lower urinary tract (LT) calculi (143) were more common than upper urinary tract (UT) calculi (71). There was an overwhelming majority of males among patients operated on for LT calculi (ratio of males:females = 1.2:1). The mean age of patients with UT calculi was 44 years, while that of LT calculi was 51 years.