In 1998, nearly 600 child occupants of motor vehicles aged younger than 4 years died in motor vehicle crashes. Yet approximately 29% of children aged 4 years and younger do not ride in appropriate child safety seat restraints, which, when correctly installed and used, reduce the need for hospitalization in this age group by 69% and the risk of death by approximately 70% for infants and by 47% to 54% for toddlers (aged 1 to 4 years). The systematic review development team reviewed the scientific evidence of effectiveness for five interventions to increase child safety seat use. For each intervention, changes in the use of child safety seats or injury rates were the outcome measures evaluated to determine the success of the intervention. Database searching was concluded in March 1998. More than 3500 citations were screened; of these citations, 72 met the inclusion criteria for the reviews. The systematic review process identified strong evidence of effectiveness for child safety seat laws and distribution plus education programs. In addition, community-wide information plus enhanced enforcement campaigns and incentive plus education programs had sufficient evidence of effectiveness. Insufficient evidence was identified for education-only programs aimed at parents, young children, healthcare professionals, or law enforcement personnel. Evidence is available about the effectiveness of four of the five interventions we reviewed. This scientific evidence, along with the accompanying recommendations of the Task Force elsewhere in this supplement, can be a powerful tool for securing the resources and commitment required to implement these strategies.