In this case report, the findings of a patient who was diagnosed as nonarteritic anterior ischemic optic neuropathy (NAION) at the age of 66 with progression within one month were mentioned. The patient was admitted to our clinic with the complaint of blurred vision, which had been in the left eye for two days. The visual acuity was 10/10 in both eyes, and visual field test revealed an inferior altitudinal defect in the left eye. Color vision was intact in both eyes with no relative afferent pupillary defect. Fundus examination revealed blurred optic disc margins and peripapillary retinal hemorrhage in the left eye. He received a 3-day course of low-dose (500 mg/day) intravenous steroid treatment (methylprednisolone) once. Three weeks later, the patient admitted to our clinic again with the complaint of superior visual field defect in the left eye. He received a 3-day course of high-dose (1 g/day) intravenous steroid treatment (methylprednisolone) followed by a tapering dose of oral prednisolone. During the follow-up period, an increase in ischemic areas in the optic nerve head was detected with Optical coherence tomography angiography (OCTA) imaging. Progression of NAION in the same eye after a short interval is a rare condition. OCTA may help to elucidate the progressive NAION etiopathogenesis and follow up of patients.