A retrospective survey was made of 305 patients with proved urinary calculi. When those patients with a solitary stone were compared with those with multiple stones no diagnostically helpful difference was noted in the prevalence of abnormal serum or urine biochemistry, urinary infection, or anatomical abnormality of the urinary tract. The same was true of the stone composition and the need for surgery. It seems that neither routine radiological examination nor regular follow-up is likely to help identify patients whose stones are going to recur.