Slow graft function (SGF) may occur during the early post-transplant period. In this paper, we present our findings regarding SGF after pediatric renal transplantation and its predictive variables. From 1985 to 2004, a total of 300 pediatric renal transplants were performed at our institution. A total of 10 cases with SGF and 50 controls that were operated by the same surgeons were enrolled in this study. The mean age of the recipients and donors was 11.4 (3-15 yr) and 28.05 yr (20-50 yr), respectively. All kidneys were retrieved from living donors. We compared patients with SGF with controls regarding four independent variables: age difference between donors and recipients, serum hemoglobin difference between donors and recipients, mean blood pressure (systolic blood pressure + 2 [diastolic blood pressure]/3) difference between donors and recipients, and weight difference between donors and recipients. The mean age of recipients was 10.5 +/- 4.1 in SGF group and 11.6 +/- 2.5 in control group (p = 0.4). The differences between donors and recipients regarding weight and mean blood pressure in subjects with SGF were not higher than other patients (42 kg vs. 37.4 kg, p = 0.4; -3 mmHg vs. -4.1 mmHg, p = 0.8). The mean hemoglobin difference between donors and recipients was 6.3 +/- 2.1 g/dL in SGF group and 6.7 +/- 2.3 g/dL in control group (p = 0.6). The differences between donors and recipients regarding age, weight, mean blood pressure and serum hemoglobin level are not predictive variables for SGF.