The authors report 6 cases of triatrial heart with various and non-specific manifestations and attribute the difficulty of its clinical identification above all to the frequency of associated lesions, which were present in 5 of the 6 cases reported here. An atrial septal defect and left superior vena cava were each seen twice while a ventricular septal defect, sub-valvular aortic stenosis, mitral insufficiency and transposition of the great vessels were each seen once. It was routine echocardiography which led to the discovery of triatrial heart in each of these 6 cases. The value of this investigation in the positive diagnosis of triatrial heart proved, in these patients, to be greater than that of cardiac catheterisation.