Keratoconus is a common corneal dystrophy in which penetrating keratoplasty is an effective form of treatment. A retrospective study on patients with keratoconus who underwent penetrating keratoplasty in the Singapore National Eye Centre between 1991 and 1995 was undertaken to describe and characterise the patient population and the success of this procedure. Thirty-two penetrating keratoplasties for keratoconus in 32 eyes of 29 patients were identified. Twenty eyes of 20 patients had a postoperative follow-up period of at least 12 months (range 12 to 44 months). These eyes were specifically examined for success rate and complications. Of the 32 eyes in the study, 18 (56%) belonged to Indians patients and 23 (72%) belonged to male patients. In those eyes with 12 months or more of postoperative follow-up, the visual acuity of 16 (80%) eyes improved postoperatively, with 14 (70%) eyes having a best corrected visual acuity of 6/12 or better. There were no graft failures. Nine eyes (45%) had complications postoperatively. Five eyes underwent refractive surgery for correction of astigmatism. Useful vision of 6/60 or better was achieved within 1 week postoperatively in 8 (40%) of the eyes. The authors conclude that penetrating keratoplasty is a successful procedure in keratoconic eyes not correctable by conservative therapy. The incidence of postoperative complications were however not uncommon. Although the majority of these complications were treated successfully, severe complications such as retinal detachment and glaucoma were the main causes of poor visual outcome after penetrating keratoplasty for keratoconus.