A combination of metoclopramide, dexamethasone, droperidol, lorazepam, and diphenhydramine was used in prophylaxis of high-dose (≥100 mg/m2) or moderate dose (≥50 mg/m2) cisplatin. Sixty minutes prior to starting cisplatin, 16 mg dexamethasone, 50 mg diphenhydramine, and 0.5 mg lorazepam were given orally (PO). Droperidol 1 mg was given intramuscularly (IM) 15 minutes prior to beginning cisplatin. Repetitive doses of intravenous (IV) metoclopramide, 2 mg/kg in 75 ml 5% dextrose in water over 15 minutes was given 30 minutes prior to, and at PA, 1½, 4½, and 7½hours after beginning cisplatin chemotherapy. Only patients with nausea and/or vomiting received subsequent doses of 2 mg/kg metoclopramide IV every 3 hours as needed. Patients refractory to metoclopramide were given 1 mg droperidol IM and 50 mg ofdiphenydramine PO every 6 hours. There were 19 men and 9 women with a median age of 58 (range 31-75) years. Complete protection from nausea and vomiting in all courses of treatment occurred in 17 (61 %) patients. In 63 % and 70 % of the 57 evaluable courses, there was neither nausea nor vomiting, during the first 24 hours after cisplatin. When present, nausea was mild and the median number of vomiting episodes was 2 (range 1-3). This antiemetic regimen was well tolerated. Toxicities were mild and occurred in 3 patients (angioneurotic edema, transient episode of facial twitching, and heaviness of tongue, respectively). The 5-drug antiemetic combination can prevent cisplatin-induced nausea and vomiting in a majority of patients.