Characterisation of an ovarian mass is of utmost importance in the preoperative evaluation of an ovarian neoplasm. It enables the surgeon to anticipate carcinoma of the ovary before the operation, so that adequate procedures are planned. Although, ultrasonography (US) remains the foremost imaging modality for screening patients with adnexal lesions, computed tomography (CT) recently has proved to be of value in the characterisation and management of tumors of the ovary. Magnetic resonance (MR) imaging has also been shown to have a high degree of diagnostic specificity for certain types of ovarian masses, such as dermoid cysts, and endometriomas. However, the potential of MR imaging to characterize tumors of the ovary has not yet been established. This study assesses the value of MR imaging and CT for the purpose of predicting the malignancy of ovarian lesions, and comparing findings of MR imaging with those of CT.