Controversy surrounding the use or misuse of the pulmonary artery catheter (PAC) remains one of the most frequently debated issues in anesthesia, critical care, and cardiology. It has been argued that the cardiovascular data it provides, its ease of insertion, and the low incidence of associated complications mandate its use in all patients undergoing cardiac surgery. Conversely, it has been suggested that clinical experience, combined with information derived from the central venous pressure (CVP) and noninvasive monitors, is adequate to diagnose and treat hemodynamic abnormalities in the perioperative period. A retrospective study addressing the specific issue of patient outcome showed a significant reduction in perioperative reinfarction rates in patients with coronary artery disease undergoing noncardiac surgery compared with historical controls. In another study of patients with left main coronary artery disease undergoing coronary artery bypass grafting (CABG), mortality was decreased from 20.0% to 3.5% in the group monitored with a PAC. In patients undergoing cardiac surgery, data derived from the PAC were shown to be a more sensitive indicator of hemodynamic abnormalities than were "routine" parameters. A definitive assessment of the usefulness of the PAC awaits further investigation.