Tenascin-C (TNC) is an extracellular matrix protein that is expressed at low levels in normal adult tissue but is highly expressed around many tumors including ovarian tumors. The objective of this study was to determine the clinical significance of the serum levels of TNC in epithelial ovarian cancer (EOC) patients. A total of 50 patients with a pathologically confirmed diagnosis of EOC were included in this study. Serum TNC levels were determined by the solid-phase sandwich enzyme-linked immunosorbent assay (ELISA) method. Age- and sex- matched 28 healthy controls were included in the analysis. Median age of the patients was 56.5 years old, range 22 to 83 years. Majority of the patients had advanced disease (FIGO stage III-IV) (90 %). The median serum TNC levels were found significantly higher in EOC patients (130.5 pg/mL) compared to healthy controls (90.1 pg/mL) (p = 0.03). We found no correlation between serum TNC levels and any prognostic parameters analyzed, including age of the patients, histology, tumor grade, stage of the disease, and response to chemotherapy. Survival analysis did not show statistically significant effect of serum TNC concentration on progression-free and overall survival (p = 0.36 and p = 0.19, respectively). However, patients with high serum TNC levels tend to have poor overall survival. In conclusion, although serum TNC levels are elevated, it has no predictive or prognostic roles on survival in EOC patients.