Abstract Background: Cystic disease of the female pelvis is com-mon, mostly of ovarian origin and it can range from simple or functional ovarian cysts to malignant tumors. Determining whether the pelvic cystic lesion is of ovarian or non-ovarian origin and the nature of the lesion, whether benign or malignant is of great importance in order to plan adequate therapeutic procedures, and may influence patient's management. MRI can provide valuable information such as lesion's morphology, signal intensity and post contrast enhancement, allowing a more complete evaluation. Aim of Study: To describe the role of conventional Mag-netic Resonance Imaging (MRI) in assessment of cystic lesions of the female pelvis and assess the ability of conventional MRI to successfully differentiate benign from malignant lesions. Patients and Methods: It is a prospective & descriptive study of conventional MRI of the pelvis in 20 female patients, aged between 18-60 years; referred to the MRI unit based on preliminary ultrasound detection of a complex cystic lesion, GI-RADS category 3 or more. Clinical evaluation was pre-formed by the referring physician. MRI pelvis was done for all patients with further pathologic correlation. The study was conducted at Ain Shams University Hospitals over a period of 6 months. Results: Conventional MRI also suggested benign pathol-ogy of fourteen out of the twenty one studied lesions; all of them were true benign. MRI had shown 93.3% sensitivity, 100% specificity, 95.2% accuracy, 100% positive predictive value and 85.7% negative predictive value in its individual performance during the assessment of the included adnexal masses. Conclusion: Conventional MR imaging proved to exhibits high sensitivity and specificity for differentiating benign from malignant complex adnexal lesions.