Forty-two patients with advanced lung cancer undergoing chemotherapy containing cisplatin (80 mg/m2) were submitted to a randomized controlled trial to evaluate the effect of the combination of metoclopramide and dexamethasone for the treatment of delayed cisplatin-induced emesis occurring more than 24 hours after cisplatin administration. All patients received intravenously (i.v.) high-dose metoclopramide and dexamethasone on the day of cisplatin treatment. Excellent emetic control (no emesis during the 24 hours following cisplatin administration) was achieved in 30 out of 41 patients (73%) with this combination. Patients treated i.v. with metoclopramide and dexamethasone on days 2-7 experienced less delayed emesis, nausea and anorexia compared to those treated with a placebo (delayed emesis, 25 vs 50%, respectively, P = 0.105; more than four days of nausea, 10 vs 35%, respectively, P = 0.059; less than three days of anorexia, 80 vs 50%, respectively, P = 0.048). Although the results of the study showed no statistically significant advantage with the combination of i.v. metoclopramide and dexamethasone for patients treated with cisplatin, in view of the short duration of anorexia and the marginal reduction in nausea. Female patients tended to have more emetic episodes and extrapyramidal side effects (except akathisia) than male patients, but the differences were not statistically significant except for acute emesis (P less than 0.005).