The results of an open study designed to evaluate the prevention of cisplatin-induced emesis by the specific 5-HT3 receptor antagonist ICS 205-930 are reported. Fifty-four cancer patients, treated with diverse chemotherapy regimens, all including cisplatin (greater than = 50 mg/m2), received ICS 205-930 for a total of 165 courses. ICS 205-930 (10 mg) was given i.v. immediately before the cisplatin infusion and a second 10-mg dose was given immediately after. In 109 courses (66%) the patients did not have any vomiting episodes. Nausea was absent in 44.8% of courses. More than 3 vomiting episodes occurred only in 17 (10.4%) courses, and severe nausea only in 11 (6.6%). ICS 205-930 was extremely well tolerated. Mild headache occurred during 7 courses (4.2%) in 4 patients, hypotension during 5 courses (3%) in 3 patients and lipothymia in 2 courses (1.2%) in 2 patients. These results suggest that ICS 205-930 is an effective and well tolerated antiemetic drug in patients receiving cisplatin chemotherapy.