Experimental data have suggested that pneumatic external counterpressure improves outcome in intra-abdominal hemorrhage by either a tamponade effect and/or elevation in central systemic blood pressure. As a result, the empiric use of the pneumatic antishock garment (PASG) has become a standard of care, even to the point where the device has been legislated as required equipment on emergency medical rescue vehicles. However, the effect of the PASG on intra-abdominal hemorrhage has not been evaluated in randomized clinical trials. The purpose of this study was to evaluate the effect of the PASG on the survival of hypotensive patients with penetrating abdominal injuries. During a 2 1/2-year period, 201 consecutive patients presenting with penetrating anterior abdominal injuries and an initial prehospital systolic blood pressure of 90 mm Hg or less were entered into the study. All prehospital care was delivered by the same municipal emergency medical services system, and all patients subsequently were transported to the same regional trauma facility. The patients were randomized into control and pneumatic external counterpressure groups by an alternate-day assignment of PASG use. The resulting study populations (control, n = 104; PASG, n = 97) were found to be well matched for survival probability indices, prehospital response and transport times, and the volume of IV fluids received. The results demonstrated no significant difference in the survival rates of the control and PASG treatment groups (81 of 104 vs 67 of 97). From these data we conclude that, contrary to previous claims, the PASG provides no significant advantage in improving survival in the urban prehospital management of penetrating abdominal injuries.