Two hundred and seventeen patients with advanced gastric cancer were classified according to the resectability of the tumour into two groups: I, resectable (non-radical surgery), 99 patients, and II, non-resectable carcinoma, 118 patients. Within each group patients were randomly assigned to receive 5-fluorouracil (5-FU) + BCG, 5-FU, or no further treatment (surgery only). BCG was given by scarification. A 2-year follow-up is reported. The group of patients with resectable tumours and receiving chemoimmunotherapy had a statistically significant prolongation of survival compared with the 5-FU and surgery only groups. No differences in survival were observed between these treatment modalities in patients with non-resectable tumour. These observations indicate that chemoimmunotherapy may be of benefit for a selected group of patients with gastric cancer.