A patient simulator has been developed for training, certification, modeling, and demonstrating problems in the management of critical-care patients. The Critical Care & Hemodynamic Monitoring Training System consists of a personal computer, software, and a replica of a human torso designed to enable students to practice critical-care medicine. The computer displays patient histories, laboratory results, treatment options, patient responses, and a real-time cardiac monitor. The torso apparatus is used to practice insertion of a hemodynamic monitoring catheter; the cardiac monitor displays catheter pressure readings as the catheter is advanced into the heart and also pulmonary artery and wedge position. Special screen calculators in the program may be used to determine hemodynamic, respiratory, ventilatory, and renal function indices. In contrast to previously described simulators and computer oriented instructional programs, this system contains no inherent data base. Instead, authors build a library of informative cases by using the hardware and software tools provided. Individual “modules” of patient information are authored, and these are transparently linked as a student undertakes management of a patient. Although this system is a technologic achievement, determination of its usefulness as an instructional tool or certification aid must come from broader use and controlled studies. © 1990, Mayo Foundation for Medical Education and Research. All rights reserved.