The present study aimed to investigate the impact of BRCA1 protein expression on the patients' outcome of ovarian serous carcinoma, and its correlation with different clinicopathologic features. Immunohistochemistry with BRCA1 was done for 80 cases of ovarian serous carcinoma that had a positive family history. Correlation with clinico-pathologic variables and patients' outcomes was investigated. BRCA1 expression was detected in 61.2% of the studied cases. A significant relation with patients' age, tumor grade and tumor stage was found (P<0.05). Also, there was a significant decrease in disease free survival (DFS) & overall survival (OS) in the positive BRCA1 group. Metastasis, recurrence, residual disease, and mortality rate showed significantly higher figures in patient with BRCA1 expression (P<0.05). Positive BRCA1 expression had proven to be associated with advanced stage & grade of tumors, as well as worsened prognostic survival parameters (metastasis, recurrence, residual disease, and mortality) in patients with ovarian serous carcinoma.