Background Venous thromboembolisms (VTEs) continue to be a leading cause of death among trauma patients. Predicting which patients will develop a VTE can be difficult. This study investigated whether the Injury Severity Score (ISS) could be used in conjunction with the Abbreviated Injury Score (AIS) to assess a trauma patient's risk for subsequent VTE development. Materials and Methods Participants were found by querying a trauma center registry. There were 2,213 patients included for evaluation. The patients were categorized based on their ISS and the anatomical region with the greatest injury (determined by the AIS). Odds ratios for developing VTEs were calculated for each ISS category. Results The results showed that in most categories VTE risk increased as ISS increased. Patients with trauma to their head/neck, chest, or extremities with ISS values of 21 or greater were all at significantly increased risk for VTE development. Patients in these categories with an ISS less than 21 seemed to have little or only moderately increased odds of developing a VTE, although these values were not statistically significant. Patients with abdominal trauma were at increased risk even with ISS values of 11-21. Conclusion Trauma to the head/neck region, chest, and extremities (including pelvis) with ISS of 21 or higher had significantly increased odds of developing a VTE. Patients with abdominal trauma of any severity appeared to have increased odds of developing a VTE.