Increasing use of endourological procedures to establish a diagnosis of pyeloureteral lesions detected as a repletion deficiency during urographic study, which when they are obstructive, affect the upper urinary tract. The present report describes the use of ureterorenoscopy as a diagnostic and therapeutic procedure for the ureteral obstruction occurring in a patient with papillary necrosis secondary to analgesics abuse. The papilla was indwelt in the right distal ureter causing obstruction and symptoms of renal colic and septicemia.