The serum levels of alpha-1-antichymotrypsin, immunosuppressive acidic glycoprotein, acid soluble glycoproteins, and sialic acid as acute phase reactants (APRs) and carcinoembryonic antigen (CEA) as a cancer-producing glycoprotein were measured preoperatively in 245 patients with gastric cancer who underwent gastrectomy and were treated with postoperative adjuvant chemotherapy or immunochemotherapy. The patients were classified into four groups: group A had normal leverl of serum CEA and APRs; group B had abnormal CEA levels; group C had normal levels of CEA and one or more abnormal levels of APRs; and group D showed abnormal levels of CEA and one or more abnormal levels of APRs. Groups A and B showed good survival rates, but groups C and D had poor rates. The patients in groups A and C who received immunochemotherapy exhibited significantly better survival rates than those treated with chemotherapy. The pretreatment of levels of CEA and APRs have potential as aids in prognosis and in the selection of suitable immunopotentiators and anticancer drugs for cancer patients.