Seatbelt usage has been consistently documented to decrease mortality and injury severity from motor vehicle crashes (MVC); however, conflicting results are available comparing mortality and injury severity, and blood alcohol positivity. Prospective testing on all MVC admissions showed that 51.5% of the non-belted, and 22% of the shoulder-belted drivers had a positive blood alcohol content (p less than 0.001). A comparison of belted and non-belted MVC drivers revealed a significantly higher mean length of stay (LOS) (p less than 0.05) and Injury Severity Score (ISS) (p less than 0.01) for the non-belted drivers. A comparison of groups positive and negative for blood alcohol revealed no significant differences in LOS or ISS, suggesting that these parameters are related to seatbelt use and not alcohol consumption.