Ovarian cancer is the eight most common cancer in the women and the deadliest gynecologic malignancy. The majority of patients (90%) are diagnosed with epithelial ovarian cancer (EOC), which is comprised by five main histotypes – high-grade serous ovarian carcinoma (HGSC), low-grade serous ovarian carcinoma (LGSC), endometrioid ovarian carcinoma (EC), mucinous ovarian carcinoma (MC), and clear cell ovarian carcinoma (CCC). The established diagnostic biomarker CA-125 is unspecific and has been shown to not be suitable for early detection. Due to limited diagnostic tools and EOC being asymptomatic in early stages (I-II), 70% of patients are diagnosed in late stages (III-IV) and therefore the disease is associated with poor prognosis. Although the histotypes have distinct clinicopathologic characteristics, first line treatment has remained the same the last four decades regardless of histotype. In this study, we aimed to profile the phosphorylated proteins of primary tumors from a cohort of 180 EOC patients comprising HGSC, EC, MC, and CCC across all stages.