SummaryIsotopic renogram has been performed in 60 hypertensive patients and the informations obtained have been compared to those from laboratory urine and blood analysis, intravenous pyelography and in 17 cases, aortography.Bilateral lesions and unilateral atrophy of the kidneys are completely confirmed by the isotopic renogram.Confirmation of the diagnosis of stenosis of the renal artery as suggested by the renogram, was only obtained in 3 cases out of 8. This observation does not reduce the interest of the radioisotopic investigation in this disease. In fact, the renogram, with the study of the morphology of both curves and the calculation of the half-time (T/2), is a basic step before aortography.