A very rare case of cardiac lipoma located in the mitral valve is presented. Clinical symptoms, diagnostic procedures, differential diagnosis and treatment are discussed, and the relevant literature briefly reviewed. The treatment of choice for these partially asymptomatic tumors is resection, and invasive diagnostic procedures such as transesophageal biopsy should be avoided. However, transesophageal echocardiography and magnetic resonance techniques are considered helpful in differentiating between benign and malignant tumors in order to plan effective surgery.