The Children's Hospital of Alabama Critical Care Transport System provides a mobile intensive care unit for interhospital transfer of critically ill pediatric patients. The transport team consists of a pediatrician, a pediatric emergency nurse, and a respiratory therapist. We studied whether it was possible to determine in advance whether it was always necessary for a physician to be on the team. The transport physician made a determination of need for a physician based on data available prior to transport (preassessment). After the transport was completed, the physician made a retrospective determination of actual need for a physician (postassessment). Over a period of eight months, 148 questionnaires were analyzed. In 108 transports (73%), there was minimal or no change in need for a physician between the pre- and posttransport assessments. Therefore, an accurate prediction of need for a physician was possible in advance. Of the remaining transports in which the determination was significantly changed, 37 (25%) indicated a decrease in actual need for a physician after completion of the transport. There was a significant increase over the prediction in the actual need for a physician in only three cases (2%).