Of 101 vitrectomies that used sulfur hexafluoride gas, 42 of 87 eyes followed up for six months had attached retinas and 28 had visual acuities of 6/240 (20/800) or better. Ocular hypertension occurred after 45 of the 101 operations and the incidence of ocular hypertension was significantly higher in eyes that received 100% sulfur hexafluoride than in eyes given lesser concentrations of gas (P less than .05). Twenty-six of 101 eyes developed transient fibrinous exudation. Ocular hypertension was significantly more common in eyes with fibrin than in eyes without fibrin (P = .001). After complicated vitrectomies, 11 eyes developed presumed central retinal artery occlusions and lost light perception on the first postoperative day. Ten of these eyes had increased intraocular pressures. Eyes with severe hemorrhagic complications from vitrectomy were most likely to develop presumed central retinal artery occlusions.