The role of molecular markers in ovarian cancer is still a matter of debate. Protease-activated receptor-1 (PAR1) might be a good marker in some types of malignant tumors and might provide useful information in diagnosis and prognosis. The objective of this study was to evaluate the serum levels of PAR1 in regard to diagnostic, predictive, and prognostic value in epithelial ovarian cancer (EOC) patients. Forty-four EOC patients were enrolled in this study. Serum PAR1 levels were determined by enzyme-linked immunosorbent assay (ELISA) method. Twenty-five age- and sex-matched healthy controls were included in the analysis. The median age of patients was 58 years old, ranging from 22 to 83 years, where most of them had advanced disease (stage III-IV) (n = 40, 91 %). The median serum PAR1 values were significantly elevated in patients compared to healthy controls (1.52 ng/ml vs. 1.13 ng/ml) (p = 0.03), whereas any clinical variables including response to chemotherapy did not associate with serum assay (p > 0.05). Progression-free survival (PFS) and overall survival (OS) of patients who did not respond to chemotherapy nor had platinum resistance in relapsed disease were poorer in the analyses. On the other hand, serum PAR1 levels showed no significant adverse effect on either PFS or OS (p = 0.43 and p = 0.49, respectively). These results proved that baseline serum PAR1 levels of patients with EOC were significantly higher than those of healthy people. However, these assays suggested no predictive or prognostic value in this group of patients.