Eighteen patients with gastric cancer in Stage IV who had failed combination chemotherapy were treated with cis-dichlorodiammineplatinum as a single agent. Objective response was observed in four patients (22%), and another two had stable disease lasting 114 and 234 days, respectively. The median duration of the response was 150 days (range, 92-186). Gastrointestinal toxicity occurred in all the patients, but leukopenia and thrombocytopenia was the major complication in patients who had been heavily pretreated. The response rate found in this study shows that cis-platinum is an active drug in gastric cancer.