A 2-year-old girl with a functionally univentricular heart associated with a pulmonary sequestration underwent right lower lobectomy after which increased lung volume with low mean pulmonary artery pressure and pulmonary vascular resistance was documented. A cardiac catheterisation performed after a subsequent total cavopulmonary connection demonstrated favourable Fontan haemodynamics. Lobectomy may have induced compensatory lung growth, contributing to the maintenance of haemodynamics favourable for the long-term success of the Fontan procedure.