One of the hidden dangers of police work is self-imposed—the failure to wear seat belts. Unfortunately, little evidence exists concerning the factors that account for why officers do not wear their seat belts. This study used a sample of 450 police officers to develop and test a framework for understanding the predictors of seat belt use. We found several factors that were associated with the frequency of officer seat belt use: the perceived likelihood of supervisors enforcing seat belt and other driving policies, organizational justice, having a departmental colleague previously struck by a vehicle, law enforcement experience, risky driving attitudes, number of prior on-duty collisions, being a patrol officer versus supervisor, and perceived risk of being involved in a vehicle collision. We discuss the practical implications of these findings as they apply to efforts aimed at improving officer driving safety and subsequent reduction in related injuries and deaths.