Objective: In this study, we aimed to assess the efficacy of direct endoscopic imaging in identifying and diagnosing lesions in patients with ureteral filling defect, obstruction and hematuria, which were not determined with standart diagnostic methods. Material and Methods: Sixty-one patients who presented to our clinic between December 1997 and April 2004 and underwent diagnostic ureterorenoscopy for ureteral lesions, which could not be identified with conventional diagnostic procedures, were included in our study and their records were evaluated retrospectively. Results: According to the history obtained from the medical records of the patients, the initial complaints were flank pain in 42 (%69) patients, microscobic hematuria in 14 (%23), recurrent urinary tract infection in 2 (%3) and incidentally diagnosed hydroureteronephrosis with different procedures in 3 (%5). Ureterorenoscopic examination in 23 (%38) patients revealed no pathology. Diagnoses were ureteral stone in 19 (%16) patients, ureteropelvic junction obstruction in 5 (%8), urotelial tumor in 7 (9612) and benign ureteral stricture in 16 (%26). Thirty-four (%56) of these patients were included in the follow-up protocol and 31 (%44) patients were treated concurrently or subsequently. No complication developed in these diagnostic approaches. Conclusions: Conventional diagnostic procedures are sometimes not sufficient for determining ureteral pathologies. In these cases, ureteroscopy is a safe and efficient method in selected patient groups, due to its advantages like low morbidity, enabling both diagnosis and treatment, and facilitating the early diagnosis of serious cases like upper urinary tract tumors.