Although cardiac myxomas are histologically benign, they may be lethal because of their strategic position. They can mimic not only every cardiac disease but also infective, immunologic, and malignant processes. Myxomas must therefore be included in the differential diagnosis of valvular heart disease, cardiac insufficiency, cardiomegaly, bacterial endocarditis, disturbances of ventricular and supraventricular rhythm, syncope, and systemic or pulmonary embolism. The symptoms depend on the size, mobility, and location of the tumor. Echocardiography, including the transesophageal approach, is the most important means of diagnosis; CT and MRI may also be helpful. Coronary arteriography in patients over 40 years of age is generally required to rule out concomitant coronary artery disease. Surgical removal of the tumor should be performed as soon as possible; the long-term prognosis is excellent, and recurrences are rare. In follow-up examinations as well, echocardiography is essential.