A review was carried out on 1000 cases of percutaneous nephrolithotomy (PCNL), Group 1 (500), 1981-1985, being compared with Group 2 (500), 1985-1988. Previous renal surgery had been performed in 17.4% of patients in Group 1 and 36% in Group 2. There were 17.2% complicated patients in Group 1 and 51% in Group 2. The stone burden included 30.2% multiple, partial staghorn and staghorn calculi in Group 1 and 47.2% in Group 2. The use of in situ stone disintegration increased from 22.2% in Group 1 to 73.4% in Group 2 and nephrostomy drainage was necessary in 29.6% compared with 75%. Post-operative complications increased from 13.6 to 24%. Stone-free rates decreased from 92 to 51%, but the addition of other methods of treatment and the inclusion of patients with stone fragments of 2 mm or less increased these figures to 98% in Group 1 and 83% in Group 2. More complicated patients with complex stones are now being referred for PCNL. These patients require multiple treatments, including extracorporeal shock wave lithotripsy (ESWL) and percutaneous surgery, in combination with other endoscopic and radiological procedures.