Adnexal lesions are routinely encountered in general practice. Ultrasound is the first line of investigation in determining the benign or malignant potential of an adnexal lesion. In the cases of classic simple cysts, hemorrhagic cysts, endometriomas, dermoids and obviously malignant lesions, ultrasound may be sufficient for management recommendations. In cases where there is an isolated adnexal lesion, without peritoneal disease or serum CA-125 elevation, and in lesions considered indeterminate on ultrasound, MR imaging with incorporation of the ADNEx MR score can increase the specificity for the diagnosis of benignity or malignancy. This article will review the imaging evaluation of adnexal lesions and how to incorporate the ADNEx MR score to help guide clinical management.