Choroidal metastasis is rare in cancer patients. Small molecules of molecular targeted agents for lung cancer with actionable mutations were reported to be palliated for symptoms caused by choroidal metastasis. Visual disturbance by choroidal metastasis significantly decreases quality of life during the patient’s remaining lifespan; therefore, radiotherapy or laser photocoagulation is proposed with consensus. However, improvement in survival with matched molecular targeted agents for oncogenic driver mutations reminds us to also be concerned with late treatment toxicities. A 30-year-old female patient previously treated with crizotinib harboring ALK rearranged non-small cell lung cancer complained of visual disturbance, fever, and bone pains undergoing anti-PD-1 antibody treatment. A decreased proportion of ALK fusion was demonstrated by fluorescence in situ hybridization in liver metastasis compared to the primary site in a chemo-naïve state. She was diagnosed with low vision, choroidal metastasis and retinal detachment. Therefore, she started alectinib treatment and both her ocular and systemic symptoms were palliated in a week. Later, she temporarily discontinued alectinib because of skin rash although the choroidal metastasis and retinal detachment resolved and she regained low vision completely at 2 weeks. She obtained partial response with alectinib for more than 5 months after recovering from skin rash.