Ultrasonography and color Doppler has been used extensively in the evaluation of transplanted kidney. The aim of this study was evaluation and comparison of the color Doppler sonography findings in remnant kidney of living donors and transplanted kidney 6-12 months after kidney transplantation In a cross sectional study we evaluated ultrasonographic (US) and color Doppler findings in 20 kidney allograft recipient and donors. Group 1: kidney donors including living (unrelated and related) donors. Group 2: Kidney allograft recipients. Color Doppler US was performed by a single sonologist from remnant kidney of living donors and transplanted kidney of recipients, 6-12 months after kidney donation and transplantation. Kidney size (including length and width) cortical thickness, Resistive Index (RI), Pulsetile Index (PI) were recorded. Statistical analysis was performed using SPSS 13 win (t test) for comparison of the results in donors and recipients. All data was presented as +/- SD and P value less than 0.05 was considered significant. Group 1: Mean age of kidney allograft recipients was 39.92 +/- 11.95 years with male to female ratio of 1/2. Mean length, width and cortex thickness of the transplanted kidney were 120.15 +/- 11.95 ml, 53.65 +/- 7.50 ml and 8.53 +/- 1.00 ml respectively. Mean RI, PI were 0.60 +/- 0.08 and 1.02 +/- 0.23 respectively. Mean serum creatinine was 1.23 +/- 0.24 mg/dl. Mean duration of renal transplantation was 7.27 +/- 1.10 months. Group 2: Mean age of donors was 25.63 +/- 3.50 years with M/F= 1/10. Mean length, width and cortical thickness were 120.77 +/- 9.28 ml, 53.36 +/- 4.52 ml and 9.04 +/-1.27 ml respectively. Mean RI and PI were 0.60 +/-0.02 and 1.07+/- 0.13 respectively. There was no significant difference in length, width, cortical thickness, RI and PI of donors and transplanted kidney 6-12 months after transplantation (P>0.05). There was significant increase in both donor's and recipient's kidney size 6 to 12 months after tranasplantation. (P<0.05, it seems that renal ultrasonografic and Doppler parameters remain stable and well in recipients body as donors body at least in short term evaluation. Long term study with more patients recommended.