Cardiac myxomas complicated with embolism were examined. Of 51 patients who underwent surgical excision of myxomas during the last 19 years, 10 patients (6 patients originated from left atrium, 4 patients originated from right atrium) had complications by embolisms. The embolism occurred in cerebral arteries (5 cases), a coronary artery (1 case), a retinal artery (1 case), and pulmonary arteries (4 cases). Patients were divided into an embolism group and a non-embolism group to investigate risk factors of embolism. Arrhythmia, diameter, narrow peducle, and tumor friability were thought to be major risk factors. Gelatinous and rough surface type tumor tended to cause embolism. Hypervascular tumors did not cause embolism. Among 10 patients, 2 patients had already had new embolism and another 2 patients had aggravated their symptoms before making diagnosis of myxoma. Myxomas should always be considered as a source of embolization, which need meticulous investigation and prompt indication of surgical resection.