UNLABELLED: This case report presents a 56-year-old female patient with Eisenmenger syndrome. The diagnosis of corrected transposition of the great arteries with ventricular septal defect (VSD) was established in 1994. Worsening of condition occurred in 2015 and was related to the severe regurgitation on the systemic morphologically tricuspid valve. The main complaints at admission to the Bakoulev Scientific Center for Cardiovascular Surgery in 2017 included fatigue and dyspnea at rest or minimal exercise. The patient was on disability and receiving diuretics. Her condition was considered New York Heart Association (NYHA) class IV. The systemic tricuspid valve demonstrated dilated fibrous annulus as well as thickened and prolapsed leaflets with regurgitation of 3-4 degree. Since regurgitation on the systemic tricuspid valve was considered the main cause of heart failure in the patient with Eisenmenger syndrome, the valve was replaced with the CarboMedics 28-mm mechanical prosthesis, with the VSD left intact. The postoperative period was uneventful. Five and half years after surgery, the patient was in NYHA class II on a specific pulmonary arterial hypertension therapy with no signs of heart failure. The function of the mechanical valve was adequate. Thus, the replacement of the systemic tricuspid valve helped eliminate heart failure and achieve compensation on a specific pulmonary arterial hypertension therapy. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12055-024-01802-w.