The present status of magnetic resonance imaging (MRI) in the evaluation of renal masses, especially as compared to computed tomography (CT) is discussed based on our experience and on a review of the literature. It is already apparent that simple renal cysts, hemorrhagic cysts, and fatty renal masses are well demonstrated by MRI. However, other modalities, and particularly CT, have similar degrees of accuracy, are more widely available, and are less expensive. So, currently, MRI has not been proven to be an optional screening method for detection of renal masses. At present, the major clinical uses of MRI are (1) the staging of renal carcinoma, in which MRI appears slightly superior to CT, (2) in patients with known contraindications to the use of iodinated contrast medium, (3) in patients with suspected renal carcinomas in which results from other imaging modalities are atypical or indeterminate, and (4) when sagittal or coronal imaging is desirable.