In a prospective study the immunohistochemically detectable tissue expression of the antigens CA-125 and CEA in 112 epithelial ovarian carcinomas and 23 borderline tumors was related to histologic features of the tumor and to patient survival. The CA-125 antigen was expressed mainly in non-mucinous tumors, with no evident association between histologic grade and immunoreactivity. CEA was expressed in mucinous tumors regardless of tumor grade. Flow cytometric DNA analysis was performed on fresh frozen tissue in a subgroup of 60 cases. There was no association between DNA ploidy or S-phase fraction and the CA-125 or CEA antigen expression. Tumor stage, size of residual tumor masses after surgery and DNA ploidy had independent associations with patient survival in multivariate log-rank analysis of prognostic factors. However, there was no association between the CA-125 or CEA antigen expression and patient survival. Thus, in ovarian carcinoma the expression of the CA-125 and CEA antigens seems to be independent of the inherent malignant potential of the tumor epithelium, while DNA analysis provides valuable prognostic information.