To determine what patient characteristics are associated with prolonged emergency department (ED) length-of-stay (LOS) for surgical critical care patients, the charts of 169 patients admitted from the ED directly to the operating room (OR) or intensive care unit (ICU) during a 6-week period in 1993 were reviewed. The ED record was reviewed for documentation of factors that might be associated with prolonged ED LOS, such as use of computed tomographic (CT), radiology special procedures, and the number of plain radiographs and consultants. ED LOS was considered to be the time from triage until a decision was made to admit the patient. Using a Cox proportional hazards model, use of CT and special procedures were the strongest independent predictors of prolonged ED length-of-stay. The number of plain radiographs and consultants had only a minimal effect. Use of a protocol-driven trauma evaluation system was associated with a shorter ED LOS. In addition to external factors that affect ED overcrowding, ED patient management decisions may also be associated with prolonged ED length-of-stay. Such ED-based factors may be more important in surgical critical care patients, whose overall ED LOS is affected more by the length of the ED work-up rather than the time spent waiting for a ICU bed or operating suite.