In 194 cases of rheumatic cardiac valve diseases (41 men, 153 women), macroscopic examination singled out 21 lesions of the tricuspid valve (11 p. 100). These lesions were found exclusively in women and were always associated with a mitral valve disease (18 cases) or a mitral and aortic valve disease (3 cases). The fairly uncommon tricuspid valve lesions were of two different types, the incidence of which did not seem to be influenced by age. There were 7 cases of moderately tight (n = 5) or tight (n = 2) stenosis (TS) and 14 cases of tricuspid valve disease (TD), where a moderately tight stenosis coexisted with a varying degree of regurgitation (TR). In subjects with pure TS the three commissures were regularly fused by fibrosis, whereas the only lesion of the tricuspid leaflets was thickening of their free border. In TD the commissural fusions were less extensive, but the fibrous thickening was retractile and invaded the entire leaflet. The other anatomical data (perimeter of the tricuspid annulus, condition of the right cardiac cavities, heart weight, etc.) were approximately the same in both types. On anatomical specimens, percutaneous dilatation seemed possible only in pure TS; TD did not lend itself to this of treatment. In most cases two-dimensional echocardiography combined with doppler ultrasound can provide an accurate evaluation of the lesions from which can be deduced roughly the possibilities of percutaneous valvuloplasty limited to pure TS.