The postpericardiotomy syndrome occurs in up to one-third of children undergoing cardiac surgery. Its treatment includes anti-inflammatory agents, diuresis, and drainage of effusions. Administration of steroids can have a dramatic effect, but is limited by adverse effects. Usually the syndrome lasts weeks only, and persistence beyond six months is exceptional. We describe a rare case of chronic postpericardiotomy syndrome, with recurrent pericardial effusions and steroid dependency, that was treated successfully with a low weekly dose of methotrexate.