Background: The OPTIMAL study found that erlotinib improved progression-free survival (PFS) versus standard chemotherapy in Chinese patients with advanced EGFR mutation-positive non-small-cell lung cancer (NSCLC). This report describes the quality of life (QoL) and updated PFS analyses from this study. Patients and methods: Chinese patients >= 18 years with histologically confirmed stage IIIB or IV NSCLC and a confirmed activating mutation of EGFR (exon 19 deletion or exon 21 L858R point mutation) received erlotinib (150 mg/day; n = 82) or gemcitabine-carboplatin (n = 72). The primary efficacy end point was PFS; QoL was assessed using the Functional Assessment of Cancer Therapy-Lung (FACT-L) questionnaire, Trial Outcome Index (TOI) and Lung Cancer Subscale (LCS). Results: Patients receiving erlotinib experienced clinically relevant improvements in QoL compared with the chemotherapy group in total FACT-L, TOI and LCS (P < 0.0001 for all scales). Erlotinib scored better than chemotherapy for all FACT-L subscales from baseline to cycles 2 and 4 (non-significant). In the updated analysis, PFS was significantly longer for erlotinib than chemotherapy (median PFS 13.7 versus 4.6 months; HR = 0.164, 95% CI = 0.105-0.256; P < 0.0001), which was similar to the previously reported primary analysis. Conclusion: Erlotinib improves QoL compared with standard chemotherapy in the first-line treatment of patients with EGFR mutation-positive advanced NSCLC.