A wide spectrum of masses can affect the heart, ranging from non-malignant entities, such as thrombi, to aggressive primary cardiac tumors, such as angiosarcomas. Echocardiography and magnetic resonance imaging have traditionally formed the mainstay techniques for assessing these lesions. Recent technological advances have seen ECG-gated multi-detector computed tomography (MDCT) emerge as a valuable complimentary technique for assessing a suspected cardiac mass because it provides high spatial resolution, fast acquisition times, and the ability to definitively characterize fat and calcification. This article reviews the MDCT features of the spectrum of cardiac neoplasms and pseudotumors and describes important diagnostic criteria.