Two cases are reported of left atrial myxoma in elderly patients, diagnosed by combined M-mode and bidimensional echocardiography. One patient was an 80-year-old man presenting with typical signs of mitral obstruction by an atrial tumor. His symptoms were erroneously attributed to chronic bronchitis until an echocardiogram was obtained. The other patient was a 70-year-old woman with atrial fibrillation of one year's duration. Left atrial myxoma, although rarely observed in the elderly, may be diagnosed easily by means of echocardiography. Some cases may prove amenable to surgical treatment.