In patients with traumatic injuries, prehospital hypotension that resolves by Emergency Department (ED) arrival is of uncertain significance. We examined the impact of prehospital hypotension (PH) in normotensive ED patients with traumatic injuries on predicting mortality and chest/abdominal operative intervention. A retrospective cohort study was conducted of consecutive patients undergoing helicopter transport to two trauma centers between 1993 and 1997. Outcomes were mortality and chest or abdominal operative intervention. Of 545 scene transports, 55 (10.1%) patients were hypotensive on ED arrival, leaving 490 normotensive ED patients. Of 490 patients, 35 (7%) had PH and 455 (93%) had no PH. Multiple logistic regression showed the PH group to have a relative risk for death of 4.4 (95% CI: 1.2-16.6, p < 0.03) and for chest or abdominal operative intervention of 2.9 (1.1-7.6, p < 0.03). In this study of normotensive trauma center patients, prehospital hypotension was associated with increased risk of mortality and significant chest or abdominal injury.