Abstract Objective To evaluate the appearance of the nerve head in patients after giant cell arteritis–induced arteritic anterior ischemic optic neuropathy (A-AION). Design Noncomparative clinical case series. Patients The study comprised 29 patients who presented with unilateral A-AION and temporal artery biopsy–proven giant cell arteritis. Stereoscopic optic disc photographs, taken of both the affected and unaffected eyes at the onset of the disease and after a follow-up period of 20.10 ± 25.36 months (median, 11 months; range, 2–102 months), were morphometrically evaluated. Main outcome measures Size and shape of the optic disc, neuroretinal rim, optic cup, and alpha and beta zones of parapapillary atrophy. Results In the eyes after A-AION, at the end of the study, the neuroretinal rim was significantly ( P = 0.002) smaller, and the optic disc cup area was significantly ( P = 0.001) larger than those of the contralateral unaffected eyes. Alpha zone and beta zone of parapapillary atrophy did not vary significantly ( P > 0.50). Conclusions A-AION, like glaucomatous optic neuropathy, results in neuroretinal rim loss and optic disc cupping. However, in contrast to glaucoma, A-AION is not associated with an enlargement of parapapillary atrophy. The reasons and mechanisms responsible for these similarities and dissimilarities are discussed. Marked clinical, morphologic, and histopathologic similarities in optic disc cupping and loss of neuroretinal rim between A-AION and glaucomatous optic neuropathy are highly suggestive of a common mechanism for the development of the two diseases (i.e., ischemia of the optic nerve head). The subject is discussed at length.