Objectives: We assessed 100 cases of living donor nephrectomies to evaluate the Accuracy of computed tomographic angiography and magnetic resonance angiography in preoperative assessment of renal arterial anatomy with the intra operative arterial anatomy. Materials and Methods: From Jan 2006 to April 2007, one hundred donors were evaluated. The 78 men and 22 women ranged in age from 22 to 36 years ( average , 29 years ) , underwent open donor nephrectomy after evaluation with CT angiography ( 63 donors ) and MR angiography ( 37 donors). Results: Accuracy of CTA in detecting the number of renal arteries was found to be 80.9 % & Accuracy of MRA in detecting the number of renal arteries was found to be 91.8 % & Specificity of CTA in detecting renal arteries was found to be 50 % & Specificity of MRA in detecting renal arteries was found to be 33.3 % & Sensitivity of CTA and MRA in detecting renal arteries was found to be 100%. Conclusion: Both CT and MR angiography are outpatient procedures with minimal risk to the patient. With an examination time of less than 1 hour, and no recuperation period, they are both less invasive than conventional angiography. Our results suggest that multislice spiral CT angiography and gadolinium-enhanced MR angiography can be used effectively for assessment of renal arteries in evaluation of living renal donors, MR angiography has the added benefits of no iodinated contrast material and no exposure to ionizing radiation.