From 1982 to 1987 sixty-three children were treated with cyclosporin A and low dose prednisolone after kidney transplantation. Patient survival rate at 4 years after transplantation was 98.3%, survival rate of living related grafts 100% (n = 10), and survival rate of cadaveric grafts 73% (n = 53). Adequate cyclosporin blood levels were achieved in all children with a dosage regimen related to body surface area. Major concerns during the observation period were the loss of glomerular filtration rate from 51.8 to 40.5 ml/min/1.73 m2, a hypertension rate of 77.8%, and hyperuricemia. Cyclosporin A-side effects were mild. Infections occurred in 11.1%. Growth retardation in prepubertal children improved by 0.74 standard deviations of normal height, and in pubertal children by 0.51. We conclude that cyclosporin A treatment in children enables excellent long term graft survival rates with improved growth rehabilitation, however, the prevention of the cyclosporin associated nephrotoxicity and hypertension remains the major problem.