Although echocardiography is the most commonly used imaging modality to detect cardiac masses, cardiac magnetic resonance (CMR) imaging gives us an overview of the entire mediastinal structure in addition to the heart and provides valuable information regarding the location, shape, and size of the mass and notably the tissue characterization and vascularity of the lesion. CMR is highly accurate for differentiating malignant lesions from benign ones. It guides the management and monitoring of the lesion size and can monitor the progression of the lesion after surgery or chemotherapy. However, it is essential to remember that pathology remains the gold standard for diagnosing the lesion. Metastases and pseudotumors (such as thrombus) are far more prevalent than primary cardiac tumors. This chapter provides an overview of a general approach to cardiac masses. We will also present a few benign primary cardiac tumors, including rhabdomyoma, lipoma, fibroma, and myxoma, cardiac thrombus, primary malignant tumor.