Growth retardation occurs commonly in children and adolescents with chronic renal insufficiency. While some children exhibit catch-up growth following renal transplantation, for many children growth remains sub-optimal. The aim of the current study was to review the factors influencing growth and final height following renal transplantation. Data from all children who had a renal transplant performed between 1985 and 1998 at the Royal Melbourne and Royal Children's Hospitals, Melbourne (n = 85), were examined retrospectively. Two children who died in the first year post-transplant and one patient lost to follow-up within 6 months of their transplant were excluded. Children with multiple grafts had only growth following their most recent graft analyzed. The mean height standard deviation score (Ht-SDS) at the time of transplantation was -2.11 (range: -5.05 to 0.27), improving to -1.50 (range: -3.67 to 1.27) at 7 yr post-transplant. On univariate analysis, the dose of cyclosporin at 6 months and at 1 and 3 yr, and the graft function at 1 yr, had a significant positive correlation with the change in Ht-SDS (DeltaHt-SDS) at each of those time-points post-transplant. At all time-points there was a strong correlation between pretransplant height and subsequent growth. A sub-group of children who were 16 yr of age or older at December 1999, and who were considered to have reached their final height, were examined to determine predictors of final height. Multiple regression analysis of clinical and laboratory parameters from the sub-group of patients > or = 16 yr of age showed that height at the time of transplant, age at the time of transplant, and final glomerular filtration rate, were significant independent predictors of growth (r2 = 0.82, p = 0.01). In addition, the immunosuppressive regimen at 1, 3, and 5 yr post-transplant had a significant effect on growth. This study confirms the importance of each of these factors for post-transplant growth.