Four cases of renal oncocytoma that had been treated at our service from 1985 to 1990 are presented herein. The renal mass had been incidentally disclosed on the IVP (2 cases), abdominal ultrasound (1), and on palpation (1). An abdominal CT scan complemented the diagnostic work up. The diagnoses of oncocytoma (1 case) and renal carcinoma (3 cases) were made based on the scan findings. The 3 patients that had been diagnosed as having renal carcinoma were submitted to radical nephrectomy. The patient diagnosed as having oncocytoma underwent surgical enucleation of the tumor. Subsequent histological examination was diagnostic of oncocytoma in all four cases. Follow-up ranging from 15 to 55 months revealed all patients are asymptomatic and tumor-free. Currently attention has been focussed on this tumor type. The diagnostic and therapeutic controversies are discussed.