SGF generally has early and long-term consequences for allograft survival. Limited studies have been performed on SGF and its complications in pediatric renal transplantation. Therefore, 230 children who received transplants between 1985 and 2005 in Labafi Nejad hospital were included in this study. SGF was defined if the serum creatinine level increased, remained unchanged, or decreased by <10% per day immediately after surgery during three consecutive days in the first week after transplantation. The children were divided into two groups: 183 children in group A (non-SGF) and 47 patients in group B (SGF). The impact of SGF on renal function within the first year, long-term graft survival and post-transplantation complications were analyzed and compared using logistic regression model and Kaplan-Meier survival analysis. The incidence of graft failure at the end of follow-up period was significantly more common in SGF group (53.2% vs. 22.4%, p < 0.001). The median survival time was 140.25 (s.e.m. = 19.35) months in group A (non-SGF) and 60 (s.e.m. = 17.90) months in group B (SGF) (p < 0.001). The graft survival rate was 94.9%, 91.9%, 83.9%, 79.2%, and 72% at one, three, five, seven, and twelve yr after transplantation in children without SGF vs. 75.6%, 53.2%, 47.2%, 40% at one, three, five, and seven yr after transplantation in patients with SGF. The results of our study showed that slow graft function could remarkably affect graft survival and worsen both short-term and long-term transplantation outcomes. Thus, the prevention of SGF is one of the most important issues in graft survival improvement.