INTRODUCTION: Renal oncocytoma is a benign tumor of the kidney, which usually occurs in middle and older age, in asymptomatic patients. Diagnosis is based on imaging tests, and the tretment is surgical. In this paper, we will demonstrate the clinical evaluation of patients with oncocytoma, as well as their survival.MATERIALS AND METHODS: We have retrospectively analysed patients who underwent surgery because of renal oncocytoma at the Department of Urology at the Clinical Hospital Centre Rijeka, between 1991 and 2015. Data were obtained using the hospital IT system IBIS, and data from the histopathological diagnosis were obtained from the documentation of the Institute of General Pathology and Pathological Anatomy at the Clinical Hospital centre Rijeka. For statistical analyses, methods of descriptive statistics were used, and the percentage of patients' survival was determined with the help of the Kaplan - Meier method. RESULTS: Out of 34 patients with renal oncocytoma, the number of male and female patients is approximately equal (17). The median age was 61 years (37-78). The median time of patients' monitoring was eight years (1-24). The median tumour size was 5.5 cm (1.8 - 12). In 32 (94%) patients, renal oncocytoma had been diagnosed accidentally. All patients had normal laboratory values and a positive ultrasound. All patients who underwent CT scans had positive CT findings. Four (12%) patients had one of the postoperative complications. Out of 16 (47%) patients, 75% had ECOG 0 and 25% ECOG 1. 33 patiens were subjected to nephrectomy, and one patient underwent tumor enucleation. Out of total od 34 patients, six of them (17.6%) died.CONCLUSION: Oncocytoma is a relatively rare tumour of the kidney. Most of the time it is asymptomatic. Since the diagnostic methods cannot distinguish oncocytoma from carcinoma, it is treated surgically. Since it is a benign tumour, the survival rate of patients with renal oncocytoma is high.