“…The wide range of incidence may be related to the duration of follow-up, as indicated by Williams (12), who found a 34 % incidence of contralateral recurrence following nephrectomy in the long term. Oppen heimer (10), Williams (12) and Sutherland (11) reported that the incidence of contralateral recur rence following conservative surgery or following nephrectomy are approximately the same. There fore, removal of the kidney does not prevent further stone development, in the contralateral kid ney.…”