OBJECTIVE To describe the physiologic alterations, evaluation, and hemodynamic management of patients in the first 24 hrs after cardiac surgery. METHODS A brief review of preoperative and intraoperative events, postoperative physiology, and a discussion of the evaluation and hemodynamic management of cardiac surgery patients postoperatively based on a review of the literature, known physiology, and clinical experience. RESULTS After cardiac surgery, patients undergo alterations in cardiac performance related to co-morbid conditions, preoperative myocardial insults and interventions, the surgical procedure, and intraoperative management. Predictable responses evolve rapidly in the first 24 hrs after surgery. Monitoring, diagnostic regimens, and therapeutic regimens exist to address the patterns of response and occasional complications. CONCLUSIONS By understanding preoperative and intraoperative events and their evolution in the intensive care unit, clinicians can effectively manage patients who experience cardiac surgery.