Erlotinib is an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor used for the treatment of advanced stage non-small cell lung cancer (NSCLC). Clinical trials have shown high efficacy of erlotinib, particularly in patients harboring activating mutations in the EGFR gene. Here we describe the case of a 42-year-old female light smoker diagnosed with EGFR mutation-positive adenocarcinoma of the left lung with pleural metastases, pleural effusion and metastases to the thoracic vertebrae (stage IV, T4NXM1). Although the patient developed resistance to erlotinib in the first line, she achieved disease stabilization lasting for 13 months as a response to erlotinib retreatment after 6 cycles of second-line chemotherapy. In conclusion, retreatment with erlotinib in our patient was effective. Therefore it should be considered as a good treatment option for patients with NSCLC harboring EGFR mutation.