Important therapeutic advances for patients with advanced non-small cell lung cancer (NSCLC) have recently occurred, and the development of targeted therapy has revolutionized the treatment of these patients. We report the case of an NSCLC patient with unknown EGFR mutation status who developed resistance to erlotinib and was treated with afatinib. After 19 months of therapy with afatinib, the patient is still in treatment and maintains stable disease. Emerging resistance to reversible TKIs is a significant problem. Oral irreversible TKIs such as afatinib may offer an effective treatment option after failure with reversible TKIs.