Objective To evaluate the CT and MR features of renal oncocytoma in order to improve the ability for recognition and ima-gingdiagnosis.Methods The CT and MR findings of renal oncocytoma in 12 patients proved by pathology were retrospectively analyzed.Results CT scans were performed in 12 patients,one of which was accompanied with the contralateral renal angiomyoliptoma.In all lesions, seven were in the right kidney and five in the left.The lesions were round or oval in shape with the diameter 1.5 cm-12.3 cm.On pre-contrast scan,the homogeneous density was found in 3,calcification in 2,and central scar tissue in 5.On post-contrast images,the parenchyma of tumor was obviously enhanced in the cortical phase.However,the enhancement was attenuated in the parenchymal phase.Seven patients underwent MRI at the same time,exhibiting iso-or hypointensity on T1 WI in 4 and heterogenous hyperintensity on T2 WI in 5.Dynamic contrast enhanced MRI demonstrated homogenous enhancement in 1 and heterogenous enhancement in others with delayed enhancement of the central scar.Conclusion Most renal oncocytomas show certain characteristics on CT or MRI, which are helpful for preoperative diagnosis and surgical therapy.