In a previous study, we have demonstrated that inhibin-production may be associated with improved survival and, also, that tetranectin (TN) is a valuable prognostic marker in ovarian epithelial cancer. We investigated the possible correlation between inhibin, tetranectin, CA-125, ovarian steroid activity and the gonadotropin levels. Preoperative serum levels of the tumor markers inhibin, tetranectin (TN) and CA-125 were measured and related to ovarian steroid function and the pituitary-gonadal axis (gonadotropin levels) in 28 postmenopausal ovarian cancer patients. The following median levels and 95% confidence limits were demonstrated for the tumor markers: Inhibin 0.4 U/l (0.2-0.9), TN 8.9 mg/l (6.8-9.2), CA-125 160 kU/l (75-687). A significant inverse correlation was demonstrated between inhibin and the gonadotropins. The Spearman correlation coefficients showed a highly significant correlation of inhibin with the examined ovarian steroid hormones except DHEAS which also has a suprarenal component. This indicates a synthesis of inhibin and the steroid hormones from the same cell compartment as known from the normal ovary and an apparently intact negative feed back mechanism. Inhibin may be produced in the normal ovary as a defense mechanism against an elevated gonadotropin level and inhibin acts by lowering the gonadotropins or by altering their biological activity. Elevated values of the tumor markers TN and CA-125 due to gonadotropin stimulation could not be demonstrated but a significant inverse correlation between TN and CA-125 was confirmed.