We describe herein two patients with epidermal growth factor receptor (EGFR) mutated non-small cell lung cancer (NSCLC) who developed cancer-associated ischemic stroke (CAIS), infarction caused by thromboembolism in the central nervous system. Case 1 was a 63-year-old man with Exon 19 deletion type EGFR mutated lung adenocarcinoma presenting with CAIS. Case 2 was a 71-year-old woman with Exon 21 L858R type EGFR mutated lung adenocarcinoma who developed CAIS during chemotherapy after EGFR-tyrosine kinase inhibitor (TKI) resistance. Although there was no recurrence of CAIS in these patients, anticancer therapy could be hampered by the comorbidity of CAIS. This can develop anytime from before clinical manifestations of NSCLC to the next treatment after EGFR-TKI resistance. The development of CAIS should be noted in patients with EGFR mutated NSCLC, who have a promising long-term prognosis. Anticancer and anticoagulant therapies as well as rehabilitation are important for patients who develop CAIS. Establishment of measurement tests to detect CAIS before onset is desired.