A 71-year-old man with dilated cardiomyopathy without clinical complaints revealed a suspicious finding in checkup. After a multimodality cardiac imaging, the suspicion of a malignant primary cardiac tumor in the left ventricle was substantiated and the patient underwent minimally-invasive cardiac surgery for tumor resection. Postoperative chemotherapy with multiple cycles of liposomal doxorubicin was established and supported by proton beam radiotherapy. Two-year follow-up revealed no disease recurrence.