Abstract  The analyses presented in this paper document the impact of a community mobilization effort in Cameroon. Between 1997 and 1998, a local non-governmental organization worked with community associations, Njangi, in one urban and one rural location to promote knowledge and positive practices concerning family planning, sexually transmitted diseases, and treatment of common childhood diseases. Based on a multi-tiered structure, the project involved selecting and training two prominent and influential members of each community as relais or middlemen. The relais then trained mobilizers from participating Njangis to provide relevant information and help to mobilize their fellow members in favor of the positive attitudes and practices promoted by the project. The project was evaluated using baseline and follow-up measurement of pertinent indicators, and service statistics. Results suggest that the intervention had significant influence in the rural location with noticeable positive effects on knowledge and practices of family planning, knowledge and attitudes about HIV/AIDS and STIs, and use of health services. In the urban location, for programmatic and extraneous factors, the intervention was not effective. The paper discusses the lessons learnt from the intervention and offers pertinent suggestions for replicating the intervention in rural settings.