In the present study, we evaluated the antiemetic effect of aprepitant in combination with 5-hydroxytryptophan(5-HT3) receptor antagonist and dexamethasone for chemotherapy-induced emesis and nausea in lung cancer patients treated with carboplatin-based systemic chemotherapy using the Functional Living Index-Emesis, an emesis- and nausea-specific quality of life(QOL)questionnaire. Patients experiencing emesis and/or nausea during and/or after previous courses of carboplatin-based chemotherapy received aprepitant in the following treatment cycle with the same anti-cancer agent. Emesis- and nausea-specific QOL aspects were significantly improved with the addition of aprepitant to the existing regimen containing dexamethasone and 5-HT3 receptor antagonist. Our result suggests that combined antiemetic treatment with aprepitant, dexamethasone, and 5-HT3 receptor antagonist is more effective in lung cancer patients receiving carboplatin-based systemic chemotherapy than dexamethasone and 5-HT3 receptor antagonist alone.