Aprepitant is a NK1 receptor-antagonist with a novel mechanism of action for chemotherapy-induced nausea and vomiting (CINV), and is recommended as a prophylactic by many international and domestic guidelines. However, domestic clinical trials of aprepitant have only been conducted using a single dose in patients who were treated with cisplatin(CDDP), and there is no evidence to support administration of aprepitant in divided doses. We administered aprepitant in divided doses to patients who were also being treated with cisplatin, ifosfamide, and irinotecan(CIC), and had CINV due to prophylactic administration of a 5-HT3 receptor antagonist and dexamethasone. This was done in order to evaluate the antiemetic effect of aprepitant. The patients with"No vomiting"increased significantly from 25% to 83%, and the"Days with nausea"in patients also decreased significantly. Consequently, administration of aprepitant in addition to current antiemetic therapy in divided doses, as well as in single doses, exhibited a greater antiemetic effect in CDDP-treated patients.