Although the prognosis of chromophobe renal cell carcinoma (CHRCC) is more favorable than that of other RCC subtypes, it is a malignant tumor with possible metastasis. On the other hand, there is only one confirmed case of renal oncocytoma metastasis. This study assessed the apparent diffusion coefficient (ADC) value derived from diffusion-weighted imaging to differentiate renal oncocytoma from CHRCC according to cell grade. The ADC values were significantly different between low-grade and high-grade CHRCCs and between oncocytoma and high-grade CHRCC. Thus, the ADC value is useful for differentiating oncocytoma from high-grade CHRCC but not for differentiating oncocytoma from low-grade CHRCC.