From July 1966 to July 1983, sixteen atrial myxomas in fifteen patients were seen at Severance Hospital. Fifteen of the sixteen myxomas were located in the left atrium and one in the right atrium. All the cases except three were correctly diagnosed preoperatively . Presently, M-mode and two-dimensional echocardiography are utilized as safe, reliable, and noninvasive imaging modalities. Echocardiography provided an accurate diagnosis in twelve cases since November 1977. In all cases, myxoma were excised successfully. On patient had reoperation and mitral valve replacement on postoperative first day due to persist mitral regurgitation after excision of left atrial myxoma. One patient had recurrence requiring reoperation 37 months after primary operation. Follow up results of each patient were excellent. [KTCS 1983;4:485-491]