Primary tumors of the heart are rare. The majority of them are benign, the left atrial myxoma being the most frequent one. Clinical appearance varies from unapparent to life-threatening complications such as stroke, acute heart failure, or even sudden death. Diagnosis and consecutive surgical treatment strongly depend on the clinical symptoms, but their extent does not correlate with the risk for serious complications. Therefore, patients with variable clinical presentation can be especially endangered. Consequent diagnostic and immediate operative therapy is essential.