BACKGROUND/AIM: Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are effective for treating non-small cell lung cancer (NSCLC) harboring EGFR mutations. However, higher tumor programmed death ligand-1 (PD-L1) expression is associated with a poor response to EGFR-TKIs, and information on the comparison between afatinib and osimertinib in PD-L1-positive EGFR-mutant NSCLC is scarce. PATIENTS AND METHODS: We retrospectively analyzed data of patients with PD-L1-positive EGFR-mutant NSCLC to compare the effectiveness of afatinib and osimertinib. RESULTS: A total of 177 patients were included in the study. The Cox proportion hazard model was adjusted for age, sex, performance status, EGFR mutation status, PD-L1 expression level, and brain metastasis, revealing that there was no significant difference in risk for progression [hazard ratio (HR)=0.99, 95% confidence interval (CI)=0.64-1.53] or death (HR=0.96, 95% CI=0.54-1.73) between afatinib and osimertinib. CONCLUSION: In conclusion, the EGFR-TKI treatment duration and overall survival after the treatment with afatinib or osimertinib were similar in patients with PD-L1-positive EGFR-mutant NSCLC in the present study.