Mitral insufficiency is unusual in patients with left atrial myxoma. A patient with myxoma of the left atrium presented with acute pulmonary edema due to ruptured chordae tendineae. Both lesions were unequivocally demonstrated by echocardiography, permitting emergency surgical correction to be undertaken without recourse to angiographic studies. Despite the rarity of acute mitral regurgitation due to rupture of chordae tendineae in association with left atrial myxoma, with only one such case previously reported, an etiologic relationship between the two disorders can be postulated. The association between the two thus should not be unexpected.