Vascular complications are common after renal transplantation. In this study correlation between Doppler sonographic indexes and transplant kidney function was evaluated. In our renal transplant unit, 244 renal transplanted patients’ data were reviewed. Doppler sonographic evaluation was done after renal transplantation during the first week of hospitalization period, in all of the cases. Resistive index (RI), pulsatility index (PI) in interlobar arteries, thrombosis of renal and lower limbs veins were determined. Serum creatinine (Cr) and serum cyclosporine levels were evaluated frequently during hospitalization. The mean age of patients was 36.50±13.33 years (142 males and 102 females). Prevalence of renal artery stenosis was 9.5%. In the patients with transplanted renal artery stenosis mean serum Cr level (2.21±1.83 mg/dl) was significantly higher than in the patients with patent renovascular tributary (1.49±1.00 mg/dl; P=0.03). RI and PI also had significant liner correlation with serum Cr (P=0.05 and 0.001 respectively). There was no relationship between cyclosporine level and panel reactive antibody with RI and PI. Re-transplanted patients had higher RI than the first renal allograft recipients (0.72±0.16 vs. 0.63±0.11; P=0.006). Serum Cr level was higher in the renal allograft recipients with Doppler evidence of thrombosis of lower limbs veins (3.1±0.98 mg/dl) than the normal recipients (1.56±1.13 mg/dl; P=0.04). RI and PI are two valuable Doppler sonographic markers for determining of renal allograft function and related vascular