Prehospital and emergency room recordings of hemodynamic vital signs frequently play a major role in the evaluation and treatment of trauma victims. Guidelines for resuscitation and treatment are affected by absolute cutoffs in hemodynamic parameters. To determine the sensitivity of various strata of systolic blood pressure and heart rate in identifying patients with major thoracoabdominal hemorrhage, a 1-year retrospective review was conducted. A third of all patients presented to the emergency department with a normal blood pressure and over three-quarters attained a normal blood pressure during the emergency department evaluation. Although the sensitivity of vital signs in identifying this group of patients improved as the variance from normal increased, standard cutoffs were relatively insensitive. We conclude that normal postinjury vital signs do not predict the absence of potentially life-threatening hemorrhage and abnormal vital signs at any point after injury require investigation to rule out significant blood loss.