Background: Malignant primary cardiac tumors are exceedingly rare, and despite surgical exeresis or chemotherapy, their prognosis remains poor. Cardiac invasion by metastatic tumors, while more common, also entails an unsatisfactory outcome. This study aimed to review patients diagnosed with malignant primary and secondary cardiac tumors in a tertiary center between 1995 and 2022. Methods: Clinical data, echocardiographic, computed tomography, and magnetic resonance assessments of tumor location and morphology, histology, treatment, and survival were retrospectively analyzed. Results: Sixty malignant cardiac tumors were diagnosed: 17 primary (A) and 43 metastatic (B) tumors. A: the most common types were angiosarcoma (41%), undifferentiated sarcoma (23%), and fibrosarcoma (18%). Patients with primary tumors were younger than patients with metastatic tumors (41 ± 13 years vs. 57 ± 18 years, p = 0.001), with no significant gender difference. The most frequent presentations were heart failure (59%) and arrhythmia (23%). The most prevalent tumor location was the right heart chambers (71%), mostly in the right atrium (35%). 47% were submitted to tumor resection, and 29% received chemotherapy. The mortality rate was 82% with a median survival of 6.0 (interquartile range: 1.0–11.8) months after diagnosis (minimum of 12 days and maximum of 19 years). One patient with fibrosarcoma underwent heart transplantation and was still alive and well after 19 years. B: regarding metastatic cardiac invasion, the most common primary tumor sites were lung carcinomas (38%), thymomas (17%), and lymphomas (14%). Presentation with pericardial effusion was common (33%). The mortality rate was 72%, with a median survival of 3.6 (1.0–13.4) months (minimum of 7 days, maximum of 5 years). Conclusion: Diagnosis of metastatic cardiac tumors was more common than that of malignant primary tumors, both with a dismal prognosis. When radical exeresis is not possible, heart transplantation can be an option with a favorable outcome in carefully selected patients with sarcomas.