Objectives. To determine the efficacy of extracorporeal shock-wave lithotripsy (ESWL) in the treatment of urinary stones in pelvic kidneys. Methods. Fourteen male patients with renal pelvic ectopia and stones were treated with ESWL monotherapy using the unmodified Dornier HM3 lithotriptor with its original generator and ellipsoid. Twelve patients were treated in the prone position using cystoscopically placed ureteral catheters to aid in fluoroscopic localization, whereas 2 patients were treated in the supine position. A review of their stone disease, ESWL treatment, ancillary procedures, outcome, and complications is presented. Results. All pelvic kidneys were free of infection and obstruction in this group. The mean stone burden was 30.2 +/- 37.8. Most patients required a single session (9 of the 14 [64%]), 2 patients required two sessions, and 2 patients required multiple sessions. The average number of shock waves per session was 1689 (range 450 to 3500), with average kilovoltage of 21.5 (range 18 to 24). Eighty-two percent of the patients followed (9 of 11) were stone-free at 3 months. No ancillary endourologic procedures were required to deal with the presenting stones. Obstructive steinstrasse complicated treatment in only 2 patients (14%) and was successfully treated by further ESWL in both patients; in 1 of them, ureteroscopy was needed. Conclusions. ESWL monotherapy of renal pelvic ectopia stones is very effective and should be considered as the first therapeutic option for these patients, provided that accurate localization of the stone treated and proper positioning of patients that ensures adequate delivery of shock-wave energy can be maintained. Copyright 1996 by Elsevier Science Inc.