To report the results of a prospective study of the incidence of peripheral visual field loss after macular hole surgery. Prospectively, 30 eyes of 30 consecutive patients with full-thickness macular holes operated on between December 1995 and April 1996 had preoperative and postoperative Goldmann visual field tests. The surgical procedure consisted of three-port pars plana vitrectomy, posterior hyaloid removal, nonexpansile fluid-hexafluoroethane (C2F6) exchange, and, in 19 of 30 patients, autologous platelet injection, followed by face-down positioning. Twenty-nine of these 30 cases were considered to be anatomic successes. Comparison of preoperative and postoperative visual fields disclosed that four patients (13%) had a peripheral scotoma, including one patient with stage 4 macular hole. Three other patients (10%) had a postoperative relative arcuate defect. Mean postoperative intraocular pressure was higher in the latter group. None of the patients complained of peripheral scotoma. Overall, seven of 30 patients (23%) had a postoperative visual field defect. Two categories of scotomas were observed: peripheral and relative arcuate. The cause of peripheral visual field loss is unclear. Increased intraocular pressure may be the cause of relative arcuate scotomas.