A 47-year-old man presented with visual loss in the right eye 8 h after the first dose of a coronavirus disease 2019 (COVID-19) vaccine developed by Pfizer/BioNTech (BNT162b2). The best corrected visual acuity (BCVA) was 20/200. Fundus examination showed dilated and tortuous retinal veins at the posterior pole, retinal hemorrhages throughout the fundus, and macular edema. Fluorescein angiography showed multiple hypofluorescent spots that appeared to be fluorescent block due to retinal hemorrhages and hyperfluorescent leakage from the retinal veins. The eye was diagnosed with central retinal vein occlusion (CRVO). For the treatment of macular edema, intravitreal injection of aflibercept (IVA) was administered and treated with one plus pro re nata regimen. Five IVAs were performed over a 10-month follow-up period, with resolution of macular edema, and the BCVA recovered to 20/20. The patient was young and had no history of diabetes mellitus, hypertension, or atherosclerotic diseases, and his blood tests showed no abnormal findings. Both antigen test and polymerase chain reaction test for COVID-19 were negative, and the antibody test was positive due to vaccination. The development of CRVO in this patient may have been related to COVID-19 vaccination, and the appropriate IVA treatment resulted in a good visual prognosis.