Cardiac tumors are a heterogeneous group of pathologic masses of the heart that contain primary tumors—benign or malignant, and secondary tumors. Metastases are significantly more frequent, mostly originating from lung, breast, gastrointestinal tract, or ovary carcinomas. Secondary cardiac tumors may be asymptomatic or may cause cardiovascular, systemic, or embolic symptoms. The study is a summary of the available knowledge on cancerous metastatic lesions of the heart. Pleural mesothelioma (48.4%), adenocarcinoma (19.5%), or squamous cell carcinoma (18.2%) of lung, breast carcinoma (15.5%), ovarian carcinoma (10.3%), and bronchoalveolar carcinomas (9.8%) are cited as the most common origin of secondary heart tumors. Masses can spread by direct tumor invasion, by lymphatic vessels, veins, or arteries. Patients with cancer and nonspecific cardiovascular symptoms should be particularly vigilant, and the possibility of metastasis in an unusual location such as the myocardium should be considered in the diagnosis. Diagnostic methods include echocardiography, cardiac magnetic resonance, computed tomography, positron emission tomography, and histologic evaluation. Treatment of choice is managing primary carcinoma, due to the poor outcomes of surgical methods.