Between 1979 and 1988, 85 penetrating keratoplasty procedures were performed in 54 patients aged 1 month to 18.2 years at the Hospital for Sick Children, Toronto. The minimum length of follow-up was 3 months. A clear transplant was obtained in 27 eyes: 7 of 16 eyes with Peter's anomaly, 0 of 8 eyes with congenital glaucoma, 2 of 5 eyes with herpes simplex keratitis, 6 of 8 eyes with corneal dystrophy and 12 of 17 eyes with traumatic corneal scars. The most recent visual acuity was best in the trauma and dystrophy groups and worst in the congenital glaucoma group. Visual acuity results were better in older children and were fair in younger children and those with postoperative complications. Although penetrating keratoplasty is more difficult in children than in adults, it has a reasonable chance of success. However, the poor outcome in the congenital glaucoma group indicates that the procedure is not warranted in such patients.