Diffusion-weighted MRI (DW-MRI) has received more attention recently, especially from uroradiologists, owing to its role in the characterization of renal lesions. Moreover, the apparent diffusion coefficient (ADC), a value calculated based on DW-MRIs, has been used to analyze renal lesions quantitatively. However, many factors influence the accuracy of the ADC value calculation during the DW-MRI procedure. In addition, it is of great interest whether DW-MRI is superior to more conventional dynamic contrast-enhanced (DCE)-MRI for the characterization of renal lesions, or whether DW-MRI combined with DCE-MRI may provide more valuable information. Here we review state-of-the-art DW-MRI for the evaluation of renal cell carcinomas, discuss factors that influence the calculation of ADC maps, examine the impact of field strength on ADC values and, finally, compare DW-MRI and DCE-MRI for imaging renal lesions.