Two hundred cases of obstructive renal failure, in which surgery was indicated to correct such obstructions, were studied during the last five years at the national institute of Urology and Nephrology. The aim of the work was to evaluate the different methods of diagnosis and management of these cases (short of renal transplantation). All patients were examined according to a standard urological sheet and underwent conventional radiological, ultrasonography, antegrade pyelography, retrograde pyelography and radionuclide scanning, when indicated. Of these 200 cases 102 had ARF and 98 had CRF. In the management of these cases haemodialysis was performed in 54 patients (28 ARF and 26 CRF) before intervention. Preliminary drainage for decompression of the urinary tract proximal to the obstruction was performed in 110 patients (61 ARF and 49 CRF). Direct surgical attack was performed in 90 patients (41 ARF and 49 CRF). Clinical and laboratory improvement was achieved in 152 patients (101 ARF and 51 CRF). The morbidity encountered in this series was 15% (4.5% ARF and 10.5% CRF) while the mortality rate was 6.5% (2.5% ARF and 4% CRF).