BACKGROUND: We have used single-contrast (intravenous contrast only) computed tomography (SCCT) for triaging hemodynamically stable patients with penetrating torso trauma. We hypothesized that SCCT safely determines the need for operative exploration. Furthermore, trauma surgeons without specialized training in body imaging can accurately apply this modality. METHODS: We retrospectively reviewed the records of patients with penetrating torso injuries at a university-based urban trauma center to establish the accuracy of SCCT in determining the need for exploratory laparotomy. The scan was considered positive or negative with respect to the need for exploratory laparotomy as documented by the attending surgeon, who may have considered the read of the on call radiologist if available. In a separate study, four trauma surgeons independently reviewed 42 SCCT scans to establish whether the scans alone could be used to determine whether operative exploration was necessary. RESULTS: Between 1997 and 2008, 306 hemodynamically stable patients with penetrating torso trauma were triaged by SCCT. Overall, SCCT predicted the need for laparotomy with 98% sensitivity and 90% specificity. The positive predictive value was 84% and the negative predictive value (NPV) was 99%. In the 222 patients with gunshot wounds, SCCT had 100% sensitivity and 100% NPV. In the 84 patients with stab wounds, SCCT had 92% sensitivity and 97% NPV. Trauma surgeon agreement in the retrospective review of 42 computed tomography scans was "nearly perfect": positive predictive value was 93% and NPV was 92% for determining the need for exploratory laparotomy surgery. CONCLUSIONS: SCCT is safe and effective for triaging hemodynamically stable patients with penetrating torso trauma. It successfully determined the need for operative intervention with appropriate clinical accuracy without the additional costs, morbidity, and delay of oral and rectal contrast. Trauma surgeons can reproducibly interpret SCCT with high-predictive accuracy as to whether patients with penetrating torso trauma require operative exploration.