Two types of local chemotherapies were combined intraoperatively with gastric resection for gastric cancer. One chemotherapy was intralymph nodal injection of mitomycin C adsorbed on small activated carbon particles suspension for lymph nodal metastases. This therapy improved the survival rates statistically significantly as compared with those of the historical control group. The other chemotherapy was intraperitoneal administration of mitomycin C adsorbed on relatively large particles of activated carbon for the prophylaxis and the treatment of peritoneal metastases in gastric cancer with macroscopically remarkable serosal infiltration. This therapy also improved the survival rates statistically significantly as compared with those of the control groups in a randomized study.