PURPOSE: The purpose of this study was to determine the value of the intrarenal resistive index (RI),measured by Doppler sonography, in order to assess intrarenal vascular resistance in autosomal dominant polycystickidney disease (ADPKD) patients. MATERIALS AND METHODS: In 26 patients with ADPKD, RI was measured by Dopplersonography and correlated with the presence of hypertension, renal function (creatinine clearance) and anatomicalrenal severity index (RSI), thus indicating renal morphologic abnormalities during B-mode sonography . RESULTS:RI was significantly higher in 18 hypertensive ADPKD patients (0.64+/-0.65) (Mean+/-1SD; range: 0.52-0.74) than ineight normotensive patients (0.59+/-0.50) ( 0.48-0.64) (p<0.05). Statistically significant inverse correlation wasfound between RI values and creatinine clearance (r=-0.45, p<0.05), and statistically significant correlation wasfound between RI values and RSI, indicating the degree of renal parenchymal involvement. CONCLUSION: RIcorrelates with the development of hypertension, renal function and renal morphologic abnormality scoring by RSIduring B-mode Doppler sonography, and measured in this way may thus be used to assess renal vaseular resistance inADPRD patients.