Combined chemotherapy has demonstrated a degree of efficacy in gastric carcinoma. As 5-fluorouracil (5FU) and cisplatinum are two of the most active drugs, we have tested the efficacy of combined 5FU and cisplatinum in a prospective phase II trial. Cycles were administered every 4 weeks and consisted of 5FU 1000 mg/m2/day 5 days continuous intravenous (i.v.) infusion and cisplatinum 100 mg/m2 on day 2. Cycles were repeated according to tolerance and efficacy. 87 patients entered the study, 57 with metastatic or recurrent tumour (M) and 30 with locally advanced gastric cancer (LAGC). The response rate for the 83 evaluable patients was 43% [95% confidence interval (CI) 30-56%]. There were four complete responses (5%), 32 partial responses (39%), 34 cases of stable disease and 13 cases of progressive disease. Responses were more frequent in patients with a good performance status (P = 0.02), with their primary located in the cardia (P = 0.003), with a non-linitis plastica tumour form (P = 0.003) or a tumour containing less than 50% of independent cells (P = 0.016). Median survival was 9 months for the total population. It was better in patients with a good performance status (P = 0.01), and those who did not have linitis plastica (P = 0.005). Toxicity was acceptable, although grade 3-4 neutropenia was reported in 22% of the cycles, mucositis in 14% and 3 patients died of septic complications. The combination of 5FU and cisplatinum is effective in terms of tumour response in advanced gastric cancer and warrants testing with the other active regimens.