The Inoue balloon was used for dilatation of tricuspid stenosis in a 74 year old woman. The valve was reached by an over-the-wire approach with a 0.025 exchange length guide wire. The Inoue stylet would not reach the tricuspid orifice because the right atrium was so large. The Inoue balloon's special dilatation characteristics allowed good positioning at the tricuspid orifice. After dilatation to 27.5 mm, the pressure drop across the valve was reduced from 12 to 5 mm Hg. Further dilatation at 30 mm, however, created moderately severe tricuspid reflux without a further reduction of gradient. The Inoue balloon is suitable for dilatation of tricuspid stenosis but small increments in dilatation size may be required for optimal reduction in gradient without creating significant reflux.