With the rapid rise in health care costs, it has become imperative that departments of health services find effective and affordable ways to prevent disease and promote health During the past 20 years, most of the major educational interventions in the US designed to prevent disease by changing behavior have not been as successful as expected. At the same time, there is increasing evidence that community participation, a central feature of the 'new public health: is a powerful component of the programs that have been successful. in this paper, we describe and evaluate an intervention that heavily involves the community The Wellness Guide is a comprehensive health promotion guide developed with community participation to improve the wellness knowledge, attitudes and behaviors of recipients. 100 000 copies of The Guide in English and a Spanish adaptation, La Guia del Bienestar, were distributed to California participants in the US Government nutrition program for low-income mothers and children (Women, Infants and Children Supplemental Nutrition Program, or WIG). interviews from three population-based samples (n = 1189, 1889 and 672, respectively) were used to compare the knowledge and attitudes of recipients and nan-recipients of The Guide from pre-distribution to 8 months post-distribution, and to assess recipients' behavior changes. Eight months after distribution, 86% of recipients reported having read all or part of The Guide, and 74% had retained it. Recipients displayed significantly improved wellness-related knowledge and attitudes compared with non-recipients, and 26% of recipients reported having modified their behavior because of The Guide. Results demonstrate that a booklet of this type, developed with extensive community participation and which addresses a broad range of health-related issues, can significantly improve people's wellness knowledge, attitudes and behaviors and contribute to state-wide health promotion.