Among the numerous modalities applied for the preoperative evaluation of donor kidneys, renal Doppler ultrasonography (DU) provides both morphologic and functional characteristics of the kidneys. Nonetheless, the variability within DU parameters of right and left kidney is a matter of controversy. The aim of this study was to determine whether any difference exists between the DU indices of the right and left kidney before nephrectomy. Retrospectively, we collected DU findings of 25 healthy potential renal transplant donors from October 2004 to July 2008. All patients underwent the renal Doppler ultrasonography (DU) and multi-detector CT angiography (CTA) before donor nephrectomy. DUS indices including peak systolic volume (PSV), resistive index (RI), pulsatility index (PI), end-diastolic volume (EDV) and acceleration time (AT) were recorded. Six donors were excluded from the present study due to the presence of supernumerary renal artery detected by CTA. The data were analyzed by SPSS for Windows version 12.0. The Wilcoxon signed rank test was used to compare the right and left kidney DU indices. All data are presented as mean values +/- SD and p value below 0.05 was considered statistically significant. Nineteen renal transplant donors were included in the current study. The mean age of donors was 28.4 +/- 3.7 years. The mean PSV, RI, PI, EDV and AT for the right kidney were 29.83 +/- 8.18, 0.58 +/- 0.04, 1.04 +/- 0.16, 11.85 +/- 3.58 and 52.52 +/- 12.44, respectively. For the left kidney, the mean PSV, RI, PI, EDV and AT were respectively as 33.63 +/- 12.42, 0.59 +/- 0.05, 1.02 +/- 0.18, 13.76 +/- 5.92 and 49.15 +/- 13.26. Statistical analysis revealed no significant difference between the right and left kidney DU parameters (p>0.05, Wilcoxon signed rank test). In conclusion, in contrast to a variation previously found for PSV between the right and left kidneys, the present study revealed that the right kidney DU indices may not differ from those of the left kidney.