Background: Ovarian cancer is third gynecologic cancer after uterine and cervical cancer . It is heterogeneous disease with different in clinical features and outcome. It is a group of many subtypes with variation in biological features that lead to differences in response to treatments, survival and recurrence rates.Aim: This study aims to detect the frequency of histological types of primary malignant ovarian tumors and to find it's clinicopathological correlation. Subject and Methods:The retrospective cross sectional study done from 1 st of July 2020 to 1 st August 2020 on data of forty cases of primary malignant ovarian tumors who were diagnosed during the last three years (from 2017 to 2020) in Mosul hospitals labs and private labs. Results: Two thirds of cases 72.5% were surface epithelial tumors , followed by germ cell tumors 15% and sex cord-stromal tumors 12.5% .The serous cystadenocarcinoma was the most common histological type in this study .About one third of the cases 30 %were seen in 51-60 years of age group, most of tumors unilateral with solid cystic in nature .The largest diameter shows in mucinous adenocarcinoma . Pelvic mass was the most presenting sign of ovarian cancer . Conclusion: Malignant surface epithelial tumors comprises the most common type of ovarian cancer and of which serous carcinoma considered the main subtype followed by mucinous cystadenocarcinoma . Advancing age increased the possibility of malignant transformation and most of cases occur over 50 years old especially the cases of surface epithelial type , most of tumors unilateral with solid cystic in nature , pelvic mass was the most presenting sign of ovarian cancer .