Transforming growth factor-beta 1 (TGF-beta 1) plays an important role in the pathogenesis of multiple malignancies, and its expression also strongly affects the outcomes of cancer patients. The objective of this study was to determine the clinical significance of the serum levels of TGF-beta 1 in epithelial ovarian cancer (EOC) patients. A total of 50 patients with a pathologically confirmed diagnosis of EOC were enrolled into this study. Serum TGF-beta 1 concentrations were determined by the solid-phase sandwich ELISA method. Thirty age- and sex-matched healthy controls were included in the analysis. Median age of patients was 56.5 years old (range 22 to 83 years). Majority of the patients had advanced disease (FIGO stage III-IV; 90 %). There was no significant difference in baseline serum TGF-beta 1 levels between EOC patients and the controls (p = 0.39). A trend to significant relationship was found between the serum levels of TGF-beta 1 and stage of disease (p = 0.06). The elevated serum TGF-beta 1 level was associated with metastatic disease. The other known clinical variables including histology, grade of histology, debulking surgery, and serum CA 125 levels were not found to be correlated with serum TGF-beta 1 concentrations (p > 0.05). Only the chemotherapy-unresponsive patients had higher serum TGF-beta 1 levels compared with responsive ones (p = 0.02). Serum TGF-beta 1 concentration was found to have no prognostic role for both progression-free and overall survivals (p = 0.42 and p = 0.09, respectively). In conclusion, although the serum level of TGF-beta 1 has no diagnostic and prognostic role, it is associated with sensitivity to standard chemotherapy in EOC patients.