Renal computed tomography (CT), 3-dimensional CT angiography (3D-CTA), and simultaneous measurement of glomerular filtration rate (GFR) by x-ray fluorescence determination of plasma contrast clearance (PCC) are alternatives to intravenous urography (IVU), renal arteriography (RA), and 24-hr urine creatinine clearance (CrCl) for evaluation of renal structure and function in living renal donor (LRD) candidates. To determine if CT, 3D-CTA, and PCC provide data comparable to IVU, RA, and CrCl, both methods were used to evaluate 23 LRD candidates. Costs were also compared. Conventional RA identified 19 accessory arteries and one case of medial fibroplasia. Each of these anomalous vessels was recognized on 3D-CTA. Venous anatomy was more clearly delineated on 3D-CTA than the venous phase of conventional RA. CT demonstrated 3 benign cysts and a single, small intraparenchymal calcification in 3 renal units. GFRs measured by PCC and CrCl were 91 +/- 4 and 132 +/- 7 ml/min/1.73m2, respectively (r = 0.64, P < 0.05). Total cost for CT/3D-CTA/PCC was 46% less than that of IVU/RA/CrCl and 40% less than RA/CrCl. CT/3D-CTA/PCC provided reliable structural and functional data at substantially less cost, discomfort, and inconvenience to the living renal donor candidate. As such, CT/3D-CTA/PCC is superior to conventional methods for evaluation of the living renal donor candidate.