<p>Background: Hepatocellular carcinoma (HCC) is an aggressive malignancy that frequently metastasizes in advanced stages, most commonly to the lungs, lymph nodes, bones, and adrenal glands. Cardiac metastasis from HCC is extremely rare, particularly involving the right ventricle. Case presentation: A 54-year-old man presented with upper abdominal pain and was found on contrast-enhanced CT to have a large mass in the right hepatic lobe and a smaller lesion in the left lobe. He subsequently underwent extended right hepatectomy and cholecystectomy, and postoperative histopathology confirmed moderately differentiated HCC. Follow-up imaging demonstrated progressive extrahepatic dissemination, including a left adrenal lesion at 1 month, pulmonary metastases and a right adrenal lesion at 4 months, and progressive bilateral adrenal metastases thereafter. At more than 7 months after surgery, echocardiography and contrast-enhanced chest CT revealed a newly developed right ventricular mass. In the context of progressive metastatic HCC, this lesion was considered highly suggestive of cardiac metastasis, although histopathological confirmation was not obtained. The patient was subsequently treated with systemic therapy and survived for 6 months after detection of the cardiac lesion. Conclusion: This case highlights the importance of considering cardiac metastasis when a new intracardiac mass is detected during follow-up in patients with advanced HCC. Serial imaging and multimodal assessment are crucial for diagnosis, particularly when pathological confirmation is not feasible.</p>