The aim of the study was to report a patient who developed acute non-arteritic ischemic optic neuropathy following conjunctival melanoma excisional biopsy. An otherwise healthy 55-year-old man presented with a 3-month history of progressively growing pigmented lesion in the left eye. Clinical examination revealed a dark pigmented conjunctival lesion adjacent to temporal limbus with an evident feeder vessel. With the initial diagnosis of conjunctival melanoma; excisional biopsy, alcohol epitheliectomy, cryotherapy (double-thaw), episclerectomy, and amniotic membrane transplantation for ocular surface reconstruction were performed. Histopathological examination confirmed the diagnosis. Four months after surgical intervention, sudden visual loss in the operated eye occurred. According to detailed neuro-ophthalmological examination, patient was diagnosed as acute non-arteritic ischemic optic neuropathy. Non-arteritic ischemic optic neuropathy is a multifactorial disease and may occur after several ophthalmic surgeries. To the best of our knowledge, this is the first reported case of non-arteritic ischemic optic neuropathy following conjunctival melanoma excision.