The MRI appearance of the ovaries varies according to age, cycle, and treatments. Functional ovarian pathologies are common, mostly represented by functional cysts, which can get complicated mainly with hemorrhage or adnexal torsion. Multimacrofollicular dystrophy can occur in the context of adhesions. A multimicrofollicular appearance of the ovary should be described on MRI as it can be part of a polycystic ovary syndrome. Ovarian hyperstimulation, fibromatosis, and hyperthecosis are benign conditions that can mimic tumors and should thus be known by the radiologist. Organic pathologies regroup all types of ovarian tumors that can arise either from the surface epithelium, germ cells, or stroma and embryological sex cords. They can be either benign or malignant. Ovarian metastases also exist, mostly originating from the digestive system. The role of MRI is to confirm the ovarian origin of the lesion, estimate the degree of malignancy, approach a histological diagnosis, and describe any locoregional extension. Several steps can be followed to guide the analysis of an adnexal mass. The conclusion of any MRI report in this setting must include the O-RADS MRI prognostic score.