The Advanced Trauma Life Support guidelines recommend an initial rapid infusion of fluid (1-2 L) in trauma and hemorrhage victims as a diagnostic procedure to aid treatment decisions. Although patient response to initial fluid resuscitation is the key to determining therapeutic strategies, the appropriate rate of infusion is not clearly defined. Ninety-nine adult (age >16 years) blunt trauma victims with hypotension were enrolled. Patients were classified into 3 groups according to hemodynamic state after initial fluid resuscitation and requirement of surgical intervention. Total volume and rate of infusion differed significantly between the groups (P < .05). Patients requiring fluid administration at higher rate were all hemodynamically unstable and required immediate surgical intervention. Moreover, rate of infusion was the best predictor of the patients who required immediate surgical intervention. Moderate fluid infusion rate should be considered to allow identification of the patient's response to initial fluid resuscitation.