Penetrating keratoplasty frequently results in postoperative astigmatism. A rabbit model was used to investigate the relationship between the ovality of the recipient bed and the resulting postoperative astigmatism as measured by keratometry. Animals were grouped based on the extent that the recipient bed deviated from a 7.25-mm diameter circle (ovality of bed). All animals received a round 7.75-mm donor corneal button. With increasing ovality of the recipient bed, there was a corresponding increase in the postoperative astigmatism at 3 months after all sutures were removed.