Postkeratoplasty glaucoma is a significant cause of visual loss after penetrating keratoplasty. Surgery for postkeratoplasty glaucoma refractory to medical treatment has been difficult and carries with it a high risk of failure of the corneal graft. Nd:YAG laser transscleral cyclophotocoagulation (Nd:YAG CPC) was used to treat 19 patients with glaucoma refractory to medical therapy after penetrating keratoplasty. The glaucoma was controlled with Nd:YAG CPC in 13 of 19 patients (68%). The mean follow-up after the first Nd:YAG CPC treatment was 17.2 $pM 8.9 months. The mean follow-up after the last Nd:YAG CPC treatment was 14.1 $pM 8.1 months. Of 14 grafts that were clear before Nd:YAG CPC, two (14%) became edematous after treatment with Nd:YAG CPC. Five patients (26%) lost two or more lines of visual acuity. One vitreous hemorrhage occurred. Intraocular pressure elevations in the periop-erative period occurred infrequently. No patient developed persistent hypot-ony after Nd:YAG CPC. Postoperative inflammation and pain were minimal. Nd:YAG CPC appears to be a viable alternative for treatment of postkeratoplasty glaucoma refractory to medical treatment.