We studied the frequency of massive suprachoroidal hemorrhage during and after penetrating keratoplasty. Nine cases of intraoperative or immediately postoperative massive suprachoroidal hemorrhage were identified in 830 consecutive patients (1.08%) undergoing penetrating keratoplasties at the Manhattan Eye, Ear, and Throat Hospital over a 2 1/2-year period. Six of the nine patients had atherosclerotic disease or hypertension, six of nine patients had glaucoma, and eight of nine patients had undergone previous intraocular surgery. Surgery was performed under general anesthesia in 714 patients, and four of these patients (0.56%) suffered hemorrhages. Five of 116 (4.3%) local anesthesia patients experienced expulsive choroidal hemorrhage. The increased resistance to venous outflow associated with retrobulbar anesthetic injection may significantly contribute to the risk of massive suprachoroidal hemorrhage.