To evaluate the role of renal duplex ultrasonography in the detection of early alte¬ration of renal blood flow in diabetic patients, we studied with duplex ultrasound 25 patients with diabetes mellitus (11 males, 14 females, their age range (28-68 years). The resistively indices (R.I) of the main renal as well as intra¬renal arteries were calculated, diabetic patients had significantly higher resistivity indices (R.I) in the intrarenal (segmental, interlobar and arcuate) ar¬teries. The study also revealed a significantly positive correlation between the (R.I) in the intrarenal arteries in diabetics and blood sugar, albumin, as well as the serum creatinine levels, while gives a non significant positive correlation with the duration of diabetes. So we conclude that the current study documented early intra¬renal hemodynamic alterations in the form of pathologically elevated intrarenal (R.I) in diabetics. This denotes the potential usefulness of duplex evaluation of the intrarenal arteries, as a noninvasive procedure, for monitoring diabetic patients to predict those at risk of diabetic nephropathy.