Percutaneous ultrasonic lithotripsy (PUL), a new technique used in the treatment of renal stones has been shown to be safe and effective with low morbidity. 54 of the 57 patients (95%) were successfully treated by this method and all were done as a single stage procedure. 39 patients (68%) in this series were either unsuitable or had failed extracorporeal shock wave lithotripsy (ESWL). No mortality occurred in this series and one patient with staghorn stone required a nephrectomy due to severe secondary haemorrhage. Though PUL is technically more difficult to perform, it is a better alternative than open renal surgery and is complementary to ESWL especially in the treatment of the more complicated renal stones.