Seventeen patients with high astigmatism ranging from 5.63 to 19.50 diopters after penetrating keratoplasty had further surgery performed to reduce the astigmatism. Twelve patients had a mean reduction of 4.70 diopters ranging from 1.75 to 10.50 diopters. Four patients had a mean increase of 4.81 diopters with a range from 2.13 to 9.00 diopters. We have found that large amounts of astigmatism can be corrected with relaxing incisions within or circumferential to the graft-host interface but the predictability of the surgical outcome is not satisfactory in all cases.