Both captopril renal scintigraphy (CRS) and conventional arteriography were retrospectively evaluated in 64 patients to study CRS efficacy in hypertensive patients with multiple renal arteries (MRA). The presence of MRA was angiographically demonstrated in 9 patients, 7 unilaterally and 2 bilaterally, with a total of 11 kidneys supplied by 2 or more arteries. Overall, 25 MRA were identified and 7 were affected by stenosis of > 50%, causing a reduction of arterial supply in 5 of 11 kidneys. CRS correctly diagnosed all five ischemic kidneys (true positives) and five of six nonischemic kidneys (true negatives); in one case in which perfusion was not reduced, the CRS diagnosis was falsely positive. In the presence of MRA, CRS proved effective in identifying renal artery stenosis of > 50%, involving either one or all the MRA. This study shows that the presence of MRA is not a drawback in the evaluation of renal artery stenosis by means of CRS.