Clinical data and hemodynamic measurements made by cardiac catheterization are presented in two patients with tricuspid stenosis of rheumatic origin. In one, pure tricuspid stenosis was proved by autopsy, and in the second the development of tricuspid stenosis and insufficiency was demonstrated by means of cardiocirculatory studies made 27 months apart. A detailed analysis of the pressure pattern characteristic of this type of valvular stenosis is given. The measurement of the stenosed tricuspid valve area by three methods is described and discussed.