From 1985 to 1992, 98 ultrasound-guided percutaneous drainage nephrostomies were performed in 74 patients with a mean age of 77 years (range: 70-88 years). The diversion was indicated because of upper urinary tract obstruction (87% of cases), urinary fistula (4%) or secondary displacement of the first PCN (9%). The initial disease was benign in 29 patients (42.5%, including 48% of renal and ureteric stones), malignant in 39 cases (53%, including 79% of pelvic cancers) and not specified in 6 cases (4.5%). PCN was performed successfully in 93% of patients and allowed improvement in renal failure and/or treatment of the initial infectious syndrome in the majority of cases. The following complications were observed: secondary displacement of the drain (13 cases), infection (3 cases), renal subcapsular haematoma (1 case). The outcome of the patients was directly related to the initial disease: 28 of the 29 patients diverted for a benign disease were still alive and the PCN drain was able to be removed in 96% of cases after curative treatment; 95% of the patients diverted for cancer had died within 13 months after PCN. Patients with previously untreated prostatic cancer had the best prognosis, as androgen suppression allowed removal of the PCN without any additional procedure, in some cases. Drainage of the upper urinary tract by percutaneous nephrostomy under local anaesthesia has a limited morbidity and a low failure rate and therefore appears to be a technique of choice, particularly in elderly patients.