PURPOSE: Combination therapy with aprepitant, serotonin receptor antagonist, and steroids improves the complete response rate of both acute and delayed chemotherapy-induced nausea and vomiting (CINV). However, it is not known whether ramosetron is suitable for administration in combination with aprepitant. Therefore, we conducted a multicenter, open-label, prospective, phase II study in order to assess the efficacy and tolerability of combination therapy with ramosetron, aprepitant, and dexamethasone (RAD) for prevention of cisplatin-based CINV in chemotherapy-naive patients with solid cancers. MATERIALS AND METHODS: Forty-one patients with various solid cancers (31 male and 10 female; median age, 59 years) who received treatment with highly emetogenic chemotherapy (median cisplatin dose, 70 mg/m(2); range 50 to 75 mg/m(2)) were enrolled in this study. Oral aprepitant (125 mg on day 1; 80 mg on days 2 and 3), intravenous ramosetron (0.6 mg on day 1), and oral dexamethasone (12 mg on day 1; 8 mg on days 2-4) were administered for prevention of CINV. RESULTS: The complete response (no emesisand retching and no rescue medication) rate was 94.9% in the acute period (24 hours post-chemotherapy), 92.3% in the delayed period (24-120 hours post-chemotherapy), and 92.3% in the overall period (0-120 hours). The absolute complete response (complete response plus no nausea) rate was 74.4% in the acute period, 51.3% in the delayed period, and 46.2% in the overall period. There were no grade 3 or 4 toxicities related to these antiemetic combinations. CONCLUSION: RAD regimen is a safe and effective antiemetic treatment for prevention of CINV in patients receiving highly emetogenic chemotherapy.