Differentiation of pathologic alterations of the adrenal glands is still a frequent and challenging problem of daily practice in radiology. Two main groups of patients have to be differentiated: those with clinical symptoms, mainly of endocrinopathies, and those in which a mass of the adrenal gland is detected incidentally. In the first group, magnetic resonance imaging (MRI) plays a minor role, although it allows to detect and often even differentiate the cause of the disease. In the second group, MRI has an excellent performance in differentiating between adenomas and non-adenomatous lesions of the adrenal glands.