Purpose: We identified the long-term outcome of ureterorenoscopic diagnosis and treatment of patients with lateralizing essential hematuria. Materials and Methods: We reviewed retrospectively 17 patients with lateralizing essential hematuria treated with flexible ureterorenoscopy (15) or flexible percutaneous nephroscopy (2) with or without biopsy and electrocoagulation. Followup was longer than 24 months (average 60, range 24 to 116) in all patients. Results: At followup 9 of the 17 patients (59%) were cured and 7 (41%) had recurrent bleeding. Discrete lesions occurred in 11 patients (64%), who were treated with electrocoagulation with 9 (82%) cured. All 3 patients (18%) with diffuse lesions had recurrent bleeding as did 2 of 3 (66%, 18% overall) with negative examinations. Conclusions: Ureterorenoscopy is an effective means of diagnosis and treatment of lateralizing essential hematuria. The majority of patients with lateralizing hematuria will have a discrete lesion that will respond to ureterorenoscopic electrocoagulation in the long term. However, if the lesions are diffuse or the diagnostic examination is unreliable recurrent bleeding is likely.