Seventeen patients with advanced gastric adenocarcinoma, previously untreated with chemotherapy, have been included in a Phase II study with idarubicin (IDA), 15 mg/m2/day, orally, for three consecutive days every 3 weeks. All cases had measurable disease. Sixteen of 17 patients are evaluable for response. Complete or partial responses were not observed. Two patients had partial response less than 50%, one patient no change, and the remaining 13 patients disease progression. The median leukocytes and platelets nadir was 3600 and 186,000/mm3, respectively. Gastrointestinal toxicity was mild. The median total cumulative dose of IDA was 90 mg/m2 (range 45-180 mg/m2). Clinical cardiac toxicity was not observed. IDA, at the dose and by the route used, is not active in gastric cancer.