The serum markers TPS and CA 125 were determined in serum, cyst fluid and ascites in ovarian carcinoma patients and in patients with benign ovarian neoplasms. The levels of TPS and CA 125 were significantly higher in malignant and benign tumor cysts and ascitic fluids than in corresponding patients sera (p < 0.005 for TPS, p < 0.0001 for CA 125). The concentrations of cyst fluid TPS and CA 125 were also usually higher in cancer patients than in patients with benign ovarian neoplasms. TPS and CA 125 were elevated in a higher proportion of ovarian cancer patients sera than in benign ovarian patients' sera (p < 0.001 for both markers). Serum preoperative TPS and CA 125 levels were significantly higher in patients with advanced disease (FIGO stage III/IV) than in patients with early stage disease (FIGO stage I/II, p = 0.002, p < 0.05 respectively). When histology was considered, small differences in the marker signals were noted for TPS and CA 125 with the exception of mucinous neoplasms, where TPS showed a markedly higher signal. These results suggest that the combined use of TPS and CA 125 could be of additive value for the identification of epithelial ovarian neoplasms. Postsurgical TPS sera levels achieved the normal values faster than CA 125 suggesting that determination of TPS concentration before and 3 days after surgery seems to be valuable for the evaluation of radical surgery.