Cardiac tumors are a very rare but heterogenous group of diseases that may reveal themselves through a variety of nonspecific cardiac symptoms that may pose a challenge to the diagnostic process. Myxofibrosarcoma is a particularly rare type of cardiac tumor that carries a poor prognosis, thus making accurate and timely diagnosis essential. A 61-year-old woman presented with fatigue and shortness of breath during mild exercise, symptoms that have progressively worsened during the previous year. Multimodality imaging consisting of transthoracic and transesophageal echocardiography (TTE and TEE), cardiac magnetic resonance (CMR), cardiac computer tomography (CCT), and fluorodeoxyglucose positron emission computer tomography (18F-FDG PET-CT) was used for the diagnosis and postoperative follow-up of a myxofibrosarcoma.