The authors report an uncommon renal oncocytoma rate stressing difficulties that modern diagnostic modalities meet in a correct preoperative differential diagnosis with nephrocarcinoma. Oncocytoma is a low multifocal involvement. Surgical treatment is the primary choice, nephrectomy about localized monofocal lesions in advisable, with short and long term positive outcomes. In ambilateral involvement case without malignancy evident signs (scarce likelihood to infiltrate nephritic capsule, without lymphoadenopathy) conservative operations with partial resections are suggested with a five years survival from 84 to 96%.