The relation between cyclooxygenase enzymes and E-cadherin, along with the roles of these markers in the prediction of survival in optimally cytoreduced serous ovarian cancer patients was investigated. Individuals who underwent primary staging surgery and achieved optimal cytoreduction (largest residual tumor volume<1 cm) constituted the study population. Specimens of 32 cases were immunohistochemically examined for cyclooxygenase-1, cyclooxygenase-2, and E-cadherin. Two could not be evaluated for E-cadherin and cyclooxygenase-1. Overall, 14/30, 19/30, and 15/32 cases were positive for E-cadherin, cyclooxygenase-1, and cyclooxygenase-2, respectively. The expressions of E-cadherin and cyclooxygenase-2 were inversely correlated (p:0.02). E-cadherin expression was related with favorable survival (p<0.001). The relation between the expression of cyclooxygenase enzymes and poor survival did not reach statistical significance. On multivariate analysis, E-cadherin appeared as an independent prognostic factor for survival. In conclusion, E-cadherin expression is strongly linked with favorable survival. E-cadherin and cyclooxygenase 2 may interact with each other during the carcinogenesis-invasion process. Further studies clarifying the relation between E-cadherin and cyclooxygenase enzymes may lead to new preventive and therapeutic targets in ovarian cancer.