BACKGROUND:Non-small-cell lung cancer (NSCLC) predominantly occurs in the elderly, a group that has been historically undertreated for various reasons such as perceived frailty and comorbidity. CASE REPORTS:A series of 5 cases is presented, illustrating the value of erlotinib as a first-line therapy option in elderly patients with adenocarcinoma, who might otherwise have been unsuitable for treatment. A summary of each case is given, along with a discussion of some interesting factors and their clinical relevance to NSCLC therapy. Dose adjustment to manage adverse events is also addressed. CONCLUSION:Erlotinib is an effective and well-tolerated treatment option for NSCLC and could offer an alternative for patients unsuitable for or not wishing to receive chemotherapy.