Advances in ureteroscopic techniques have made it possible to treat many upper-tract tumors conservatively. Such treatment has demonstrated acceptable survival and renal preservation in high-risk patients, particularly those with a solitary kidney, bilateral tumors, poor renal function, or prohibitive operative risk. It is also preferred in patients with grade I TCC, particularly when located in the distal ureter. For patients with regionally extensive upper-tract urothelial neoplasms, use of endourologic techniques should be considered to control hemorrhage, relieve obstruction, and preserve as much functioning renal tissue as possible. Success with small, solitary, low-grade tumors allows the application of this technique to patients with a normal contralateral kidney on an elective basis. Adjuvant BCG or mitomycin C therapy appears to be safe, but confirmation of any benefits awaits the results of larger trials. Benign neoplasms can occur in the upper urinary tract and should be distinguished from TCC, thus avoiding more radical treatment for a benign lesion. Endoscopic surveillance should be maintained because recurrences can develop without radiographic evidence.