We examined 15 eyes of ten patients with complications of hexagonal keratotomy, which included glare, photophobia, polyopia, fluctuation in vision, overcorrection, irregular astigmatism, corneal edema, corneal perforation, bacterial keratitis, cataract, and endophthalmitis. Wound healing abnormalities and anterior displacement of the central cornea adjacent to the incisions were common. Eight eyes lost best-corrected visual acuity of two or more Snellen lines. Three eyes required penetrating keratoplasty for visual rehabilitation. Histologic analysis of two of these corneas disclosed variations in wound depth and abnormalities of wound configuration, including considerable wound gaping. Hexagonal keratotomy appears to be an unpredictable, unsafe surgical procedure with a high complication rate, and it should be abandoned until well-controlled experimental trials establish its safety and efficacy.