Pulmonary blastoma, a rare malignant lung tumour, can metastasise to the brain. However, there is no evidence for any effective treatment. The aim of this report is to discuss the treatment options for pulmonary blastoma and confirm the necessity for a pathological diagnosis. A 75-year-old man was admitted with progressive right-sided hemiplegia and aphasia. MRI showed multiple brain tumours. A left frontal lobe lesion was surgically resected, after which he underwent whole brain radiation (30 Gy/10 fractions). He died of an acute exacerbation of interstitial pneumonia. On performing autopsy, partial responses in the brain metastases that had been irradiated were confirmed pathologically. Thus, we present pathological confirmation that surgery and radiation therapy have therapeutic effects on brain metastases from pulmonary blastoma.