Injuries are the leading cause of morbidity and mortality confronting U.S. military forces in peacetime or combat operations. Not only are injuries the biggest health problem of the military services, they are also a complex problem. The leading causes of deaths are different from those that result in hospitalization, which are different from those that result in outpatient care. As a consequence, it is not possible to focus on just one level of injury severity if the impact of injuries on military personnel is to be reduced. To effectively reduce the impact of a problem as big and complex as injuries requires a systematic approach. The purpose of this paper is to: (1) review the steps of the public health process for injury prevention; (2) review literature on evaluation of the scientific quality and consistency of information needed to make decisions about prevention policies, programs, and interventions; and (3) summarize criteria for setting objective injury prevention priorities. The review of these topics will serve as a foundation for making recommendations to enhance the effectiveness of injury prevention efforts in the military and similarly large communities. This paper also serves as an introduction to the other articles in this supplement to the American Journal of Preventive Medicine that illustrate the recommended systematic approach.