Systemic and local immunological responses were studied in patients with or without preoperative administration of chemotherapeutic and/or immunotherapeutic drugs for colorectal cancer. The plasma TGFbeta and other cytokines such as IL-2, IL-4, IL-6, IL-10, IL-12, IFN-gamma in the supernatant fluid of culture of peripheral blood mononuclear cell (PBMC) and regional lymph node were measured by the ELISA method. A systemic response of cytokines was as follows: the production of plasma TGFbeta increased in many cases by chemotherapeutic drugs with a significant elevation of the mean production. Productions of IFN-gamma, IL-2, IL-12 in the supernatant fluid of culture of PBMC increased in many cases by immunotherapeutic drugs, and that of IL-4, IL-6 increased in many cases by chemotherapeutic drugs. A local response of cytokines was as follows: the production of IL-2 by immunotherapeutic drugs was greater than that without immunotherapeutic drugs whereas the production of IL-10 by immunotherapeutic drugs was smaller than that without immunotherapeutic drugs.