To report a case of bilateral retinal vasculitis in a patient with non-small cell lung cancer undergoing treatment with osimertinib. A 58-year-old woman with lung adenocarcinoma (T4N3M1a stage IV) presented with blurry vision in both eyes (OU). Eighteen months before symptom onset, the treatment was changed from afatinib (20 mg/day) to osimertinib (80 mg/day) because of tumor progression. The visual acuity was 20/30 and 20/25 in the right and left eyes, respectively. Clinical examination revealed few anterior chamber cells, 2+ vitreous cells, haze, and multiple retinal hemorrhages in the peripheral retinas (OU). Fluorescein angiography revealed retinal vasculitis with a severely non-perfused area in the periphery. These findings indicated hemorrhagic occlusive retinal vasculitis (HORV). Osimertinib was reduced to 40 mg/day, and oral prednisolone was started at 30 mg/day. This improved retinal vasculitis; however, the ischemic area did not improve. Pan-retinal photocoagulation was performed while tapering the oral prednisolone to 10 mg/day. Although macular edema (ME) occasionally occurred (OU), systemic and local treatment with steroid-stabilized HORV and ME helped increase the dose of osimertinib to 80 mg/day without cancer progression for 18 months. Her visual acuity remained 10/20 (OU). Osimertinib, a third-generation tyrosine kinase inhibitor, can be used to treat advanced non-small cell lung cancer with epidermal growth factor receptor mutation-induced bilateral HORV. This adverse effect can be managed with systemic and local steroid treatment and continued osimertinib administration.