To provide guidelines for admission, discharge, and triage of adult patients to the intensive care unit (ICU), based on expert opinion and the relevant literature. Publications relevant to the admission, discharge, and triage of patients to the ICU were obtained from the medical literature. Not applicable. Articles were reviewed and the relevant information extracted for analysis by an expert panel. The articles were reviewed and graded levels of recommendation made based on a rating system described in the text. Although little scientifically rigorous data exist validating the criteria for admission, discharge, and triage of adult patients to the ICU, current literature and expert opinion support guidelines to streamline the admission, discharge, and triage process. (Crit Care Med 1999; 27:633-638)