Serum cancer antigen (CA) 125, CA15.3, CA19.9, carcinoembryonic antigen and tissue polypeptide antigen were analyzed in 100 normal subjects, 47 patients with benign gynaecological diseases and 97 patients with endometrial cancer. The incidence of individual elevated tumour markers (> 2SD) was 21.5-30.9% in cancer patients. Elevations of CA125 and CA15.3 were significantly associated with poor prognostic clinical factors. Univariate anaylses showed that elevated CA125, CA15.3 and CA19.9 were significantly associated with shorter survival. In multivariate analysis, CA15.3 was highly significant and had a larger hazard ratio. In conclusion, CA15.3 is a useful marker for the prognosis of patients with endometrial cancer.