Tumor specimens from 92 patients with ovarian carcinoma were analyzed for estrogen receptor (ER), progesterone receptor (PR), proliferative fraction, and ploidy. Seventy-one percent of tumors were either ER+ (greater than 5 fmole/mg protein) or PR+ (greater than 10 fmole/mg protein) with 27% of tumors overall being both ER+ and PR+. There was no significant relationship between receptor expression and stage, grade, or histological subtype. Thirteen percent of diploid tumors were receptor negative in contrast to 38% of aneuploid tumors (P less than 0.01). There was no significant association between ER status and ploidy, but 60% of diploid tumors were PR+ in contrast to 33% of aneuploid tumors (P less than 0.02). Eleven percent of tumors overall were both ER rich and PR rich and comprised 23% of diploid and 5% of aneuploid tumors (P less than 0.01). Receptor-negative tumors had a median S phase of 18.8% which was significantly higher than the median S phase of 12% in receptor-positive tumors (P less than 0.02). A similar analysis was also performed on specimens from 9 patients with borderline epithelial ovarian tumors and 12 with benign epithelial ovarian tumors. Up to 50% of benign and borderline epithelial tumors had measurable receptors, but all were diploid with a relatively low S phase fraction. The functional significance of steroid receptor expression in ovarian cancer is unclear, but the association with ploidy and proliferative activity particularly in patients with malignant ovarian tumors may allow better identification of prognostic subsets and aid in selection of patients for hormonal therapy.