OBJECTIVES: For years, the reference standard in the evaluation of living donor vascular anatomy has been selective renal angiography (SRA). Because of the potential morbidity associated with SRA, we prospectively evaluated magnetic resonance angiography (MRA) in the assessment of renal donors. METHODS: All patients had SRA and 53 renal units were prospectively evaluated by MRA. We used SRA supplemented by findings at donor nephrectomy (DN) as our standard. We defined a positive test as the detection of any abnormality in the number of renal arteries. RESULTS: Selective renal angiography yielded a sensitivity of 86%, specificity of 95%, positive predictive value (PPV) of 75%, and negative predictive value (NPV) of 97% compared with findings at DN. MRA had a sensitivity of 64%, 88% specificity, 58% PPV, and 90% NPV. MRA correctly identified only 7 of 11 renal units with accessory arteries. MRA also incorrectly identified 5 accessory arteries not present on SRA or DN. Two patients diagnosed with fibromuscular dysplasia by SRA were missed using MRA. CONCLUSIONS: We have shown that MRA is not capable of replacing SRA as the reference standard in renal donor imaging.