The case is presented of a patient with congenital tricuspid stenosis who was treated successfully by a palliative open operation. The preoperative diagnosis was tricuspid atresia. At operation, however, congenital tricuspid stenosis was detected and managed by commissurotomy.. The postoperative course was very good. Later, the associated ventricular septal defect (VSD), pulmonary annular stenosis, and probably the atrial septal defect (ASD) will be corrected. We emphasize the importance of diagnosing congenital tricuspid stenosis correctly, because of the possibility of operating upon the valve itself.