A 42-year-old woman affected by pulmonary atresia came to our attention complaining of dyspnea and fatigue for minimal efforts with important desaturation. After assessing her basal functional capacity with a cardiopulmonary exercise test, the patient was enrolled in an extremely individualized rehabilitation program, which entailed a discreet improvement in the quality of life indices, in the absence of side effects. This paper shows that even patients with extremely severe forms of congenital heart disease, when clinical stable, can undergone a tailored cardiorespiratory rehabilitation program. This must be carried out in a monitored environment and under the supervision of expert personnel.