Children with renal transplants often have short stature. Previous studies have determined that catch-up growth is unlikely in almost 78% of children ages 0-18years post-transplantation, and will not occur in the presence of chronic rejection. Recombinant human growth hormone (rhGH) has been used successfully to increase growth rates in children with chronic renal failure. The use of rhGH in the growth retarded pediatric renal transplant recipient is potentially beneficial in promoting catch up growth. Early reports of rhGH treatment in this population indicate that there may be an associated increase in the rate of acute rejection episodes as well as an increase in the rate of progression of allograft dysfunction and earlier onset of graft failure (1,2). The overall objective of this multi-center study is to evaluate the efficacy of growth promotion and safety of rhGH use in the pediatric renal transplant population. We will conduct a randomized controlled trial of rhGH use in 200 renal transplant patients with stable graft function at least one year out from transplantation. The effect of rhGH on growth parameters will be evaluated. Secondly we will monitor serial serum creatinines to assess effects of rhGH on allograft function. We will perform kidney biopsies at entry into the study and at the time of a clinical rejection episode to determine whether rhGH affects the incidence of acute rejection.