Injuries from falls are a leading cause of emergency visits, hospitalizations, and deaths in older US adults, resulting in total lifetime costs of more than $19 billion in 2000. Fall injuries reduce independence and mobility, and increase disability and institutionalization. There is good evidence that community-based group exercise classes focusing on strength and balance prevent older adult falls, but uptake is limited. This study will test a new approach to promote participation in group balance-retraining exercise classes, targeting older adults in faith-based congregations. The proposal addresses national research priorities to evaluate strategies for dissemination and implementation of effective interventions to prevent falls among community-dwelling older adults. Focus groups and key informant interviews will provide research-based understanding of church members aged 60+ and those who influence them, and explore facilitators and barriers to class participation. With this formative research, a targeted social marketing program will be developed to motivate participation. Behavioral change and social marketing theories form the intervention's theoretical basis and will guide program design. The marketing program aims to increase class attractiveness, usability, and uptake by reducing barriers or costs and using incentives or other benefits to reinforce participation. Churches, representing varied denominations and communities, will be randomly allocated to intervention (marketing program implementation) or control (no program) groups. Outreach to diverse churches will ensure that materials and strategies target potentially hard-to-reach (e.g., Hispanic, rural) populations. The trial will test whether older adult members of intervention churches are more likely to join balance retraining classes. Factors that may mediate intervention effects will be examined. Secondary outcomes include baseline fall risk among class participants, assessed by physical function tests; and intensity, diffusion, message penetration and acceptability of the marketing program, and persistent facilitators and barriers to class participation, evaluated with process measures, focus groups, and structured interviews.