A 56-year-old male patient complaining of productive cough, hoarseness, and fatigue was found to have extensive disease of small cell lung cancer (ED-SCLC), with staging of cT4N3M1(PUL). He was treated with chemotherapy. While undergoing treatment with chemotherapy, he complained of a right visual disturbance, and choroidal metastasis was diagnosed. Because the primary site responded well to chemotherapy alone and the visual disturbance did not worsen, the patient refused radiotherapy to the choroidal metastasis. Two months after the first diagnosis of the choroidal metastasis, while he was receiving the first treatment regimen for SCLC, the visual disturbance suddenly worsened; emergent radiotherapy was started, with a total dose of 40 Gy, given as 2.0 Gy/fraction per day. The visual disturbance never improved, and the patient lost 80% of his right visual field. Within 6 months of diagnosis, the patient became blind in his right eye. The patient died of septic shock related to treatment received during his third chemotherapy regimen. Choroidal metastasis is very rare with extraocular malignant tumors, though it is common with intraocular malignant tumors. Choroidal metastasis secondary to SCLC has a poor prognosis, but in order to maintain quality of life during the patients' remaining lifespan, aggressive treatment would appear appropriate for these patients, because SCLC is a chemo-sensitive cancer.