The aim of this study was to determine the sensitivity and specificity of two non invasive methods for the diagnosis of renal artery stenosis, compared with renal angiography. Retrospective analysis of 113 hypertensive patients who underwent renal angiography permitted us to evaluate the results of echo-Doppler (n = 53) and helical computed tomography angiography (n = 50). Regarding echo-Doppler, sensitivity and specificity were 0.75 and 0.86 respectively (40 true positives/53 stenoses, and negative result in 38/44 normal arteries). Regarding helical CT angiography, these values were 0.94 and 0.95 respectively (positive result in 45/48 stenoses, and 41 true negatives/43 normal arteries). These results suggest that echo-Doppler and helical CT angiography are two reliable methods for the diagnosis of renal artery stenosis. Thus, renal angiography could be reserved for patients who may require percutaneous transluminal renal angioplasty.