Percutaneous antegrade pyelography guided by ultrasonography and fluoroscopy was attempted in 25 patients with supravesical obstructive hydronephrosis and suctessful in 23 patients to evaluate the site and nature of urinary obstruction. The etiology of the obstructive uropathies were urinary stricture in 11 cases,urinary Tbc. in 5 cases, urinary stone in 3 cases, uterine prolapse with cystocele, pyonephrosis, ureteral metastatic testicular carcinoma in 1 case respectively. No significant complication of the percutaneous antegrade pyelography was observed. Percutaneous antegrade pyelography provides significant diagnostic informations on the obstructive lesion and can be accomplished with ease and safe in patients with obstructiv hydronephnosis as a diagnostic procedure of choice in infants and children or as an alternative to a retrograde pyelography.