For the diagnosis of allograft artery stenosis in recipients of a renal transplant with hypertension a noninvasive investigation such as echo-Doppler is preferable to invasive methods such as angiography. Therefore we analyzed our experience with echo-Doppler diagnosis of renal allograft artery stenosis. In 131 renal transplant recipients with hypertension echo-Doppler examinations were performed. During the examinations several features indicative of stenosis were measured, and intrarenal Doppler spectra were quantitatively analyzed with a user-written program. Four patients showed signs of iliac artery stenosis. In 12 patients a renal allograft artery stenosis was suspected on echo-Doppler examination. In 8 of these 12 patients angiography was performed. All these showed a stenosis, 6 of which had more than > 75% stenosis. In 8 patients with normal echo-Doppler findings angiography was performed because of highly suggestive clinical signs of stenosis. In 7 of these no stenosis was found and in one a 50% stenosis was found. Comparison of quantitative Doppler spectrum features from patients with (n = 6) and without severe (> 75%) stenosis on angiography (n = 10) showed significant differences in several Doppler parameters. Subsequently an analysis of the best differentiation between these to groups on the basis of quantitative Doppler criteria was performed. In conclusion, echo-Doppler examinations with quantitative analysis of Doppler spectra enables reliable identification of renal allograft artery stenosis.