We describe a syndrome of fever, pericarditis, and symptomatic pericardial effusion beginning 2 months after transvenous insertion of a permanent pacemaker in a 75-year-old woman. The syndrome improved dramatically following pericardiocentesis and resolved after subsequent administration of indomethacin. Although right ventricular perforation during pacemaker insertion was not recognized, inadvertent perforation leading to the postcardiotomy syndrome is postulated.