1. Intravenous excretory urography was modified and expanded in order to visualize the aorta and the renal arteries. 2. The new procedure consists of the rapid intravenous injection of contrast medium, determination of the circulation time between the injection site and abdominal aorta, tomography with a multileaf cassette with five films (angiotomography) and continuation of the investigation as with routine excretory urography. 3. In 343 patients a total of 739 single or multiple renal arteries were identified at least partially. Of these, 83% could be clearly outlined between the aorta and the first division. 4. In 71 hypertensive patients angiography and angiotomography were separately evaluated. With angiotomography all 165 single or multiple renal arteries seen with angiography were visualized at least partially, whereas a total of 149 (90%) of renal arteries could be completely outlined between the aorta and the first division of the renal arteries. 5. A sensitivity for the presence of renal artery stenosis of 92% and a specificity for the absence of artery stenosis of 99% can be calculated for angiotomography in the diagnosis of renal artery stenosis. 6. Thus this method permits the detection or exclusion of renal artery stenosis in almost three-quarters of patients with hypertension, without angiography.