A Duplex-Scanner was used to screen 62 patients with severe hypertension, queried renovascular. Ten results were technically unsatisfactory and in the remaining 52 highlighted flow alterations in the renal arteries of 29 patients were found. Control angiographies confirmed renal artery stenosis in 27 cases. Comparative statistical analyses proved the test to be both highly sensitive and specific, considering other screening methods currently used in diagnosing renovascular hypertension--which include endovenous digital subtraction angiography. Results confirmed the Duplex-Scanner as a reliable renovascular hypertension screener as well as being a non-invasive method with no potentially toxic effects.