To study the value of advanced life support (ALS) compared with basic life support (BLS) for penetrating and motor vehicle crash (MVC) patients, data were collected from eight hospitals over 24 months on 781 consecutive patients with Injury Severity Scores > or = 10 as well as on a subset of 219 hypotensive patients. Initial prehospital Revised Trauma Scores (RTSs) were compared with initial emergency department RTSs. Scene times, total prehospital times, and the use of a pneumatic antishock garment (PASG), intravenous fluids, and endotracheal intubation were also documented. A modified TRISS method was used to compare mortality rates. The MVC ALS patients showed improvement in mean RTSs between prehospital and the emergency department while MVC BLS patients did not. Mean changes in blood pressure (BP) and the percentage of patients with improved BP were significantly higher among patients who received ALS; ALS was associated with increased use of PASGs and IV fluids. There were no differences between groups with respect to observed versus predicted mortality. Similar results were found in the hypotensive subset of patients. No benefit from the use of ALS for trauma patients with total prehospital times of less than 35 minutes was documented.