Pulmonary venous obstruction is a rare complication after total cavopulmonary connection by intraatrial grafting. We experienced this complication in two patients. In one of them, a large prosthesis produced inflow obstruction of the dominant ventricle and was successfully replaced with a smaller tube. In the other patient, the intraatrial tube had become severely adherent to the common pulmonary venous orifice and was removed entirely. Conversion to an extracardiac Fontan circulation was later successfully established.