The pulmonary artery catheter (PAC) has revolutionized the care of critically ill patients by allowing physicians to directly measure important cardiovascular variables at the bedside. The relative ease of placement and the important physiological data obtained by PAC led to its incorporation as a central tool in the management of critically ill patients in intensive care units. Given the lack of demonstrable benefit in randomized clinical trials, persistent questions about safety, and recent advancements in noninvasive imaging modalities that purport to more accurately estimate cardiovascular hemodynamics, the use of the PAC has declined rapidly over recent years. Devised by cardiologists to measure hemodynamic parameters in patients with acute myocardial infarction, the PAC was quickly and enthusiastically adopted by intensivists, anesthesiologists, surgeons, and other specialists. This unbridled proliferation may have resulted in negative publicity surrounding the PAC. This article systematically reviews the evolution of PACs, the results of nonrandomized and randomized studies in various clinical conditions, the reasons for its decline, and current indications of PAC.