Nine patients underwent magnetic resonance imaging (MRI) as part of the diagnostic evaluation for cardiac masses; eight of them had been preliminarily studied by 2D-echocardiography (US). MRI did not add to the US diagnostic information in patients affected by intracavitary masses. It represented the definitive diagnostic modality in two patients with intramural pathology: one with ventricular rhabdomyoma, the second with an echinococcyal cyst located within the left atrial wall. The complementary role of MRI to US in cardiac masses is discussed.