Acute disseminated intravascular coagulation (DIC) is a severe complication of gastric adenocarcinoma, and most of the patients die within 1-3 weeks. We have treated five such patients with an empirical non-myelosuppressive HDFL regimen (weekly 24h infusion of high-dose 5-fluorouracil 2600 mg/m2 and leucovorin 300 mg/m2). Within 2 weeks of starting the treatment the clinical and laboratory evidence of acute DIC quickly resolved in all five patients. HDFL not only caused no further myelosuppression, but also resulted in normalization of the patient's haemogram within a few weeks. Other anti-cancer drugs could then be safely added. Three patients had a survival time of more than 6 months. We suggest that HDFL is an ideal initial treatment for gastric cancer complicated by acute DIC.