An attempt was made to study the influence of social networks in Sri Lanka by identifying, selecting, and training volunteers to serve as informal educators of their own social networks. These educators who each were to serve a cluster of 20-25 families were young adults; the majority were females linked to health, education, or community development staff and institutions. The pattern of health care use within the small population units was observed. The process of seeking care seemed to be mediated by an amorphous system of advisors, providers, and supporters within the immediate family and significant others within the family cluster--with females and males playing distinct roles. After a three-month training period, the volunteers were studied through longitudinal surveys as they tried to improve the quality and quantity of interaction within the families to promote better health care. It was found that the volunteer health worker system for education and intervention provided a mechanism to grasp latent opportunities within communities to bring about changes in health behavior. The value systems within different organizational contexts were reflected in the performance of the volunteers; the health-linked volunteers demonstrated the clinic approach in immunization and antenatal care, while organizational activities were highlighted by volunteers linked to the community development system. The school system seemed to nurture the self-care role best and to be even more effective than the formal health care system in the promotion of preventive care. The study suggested that a group of young, predominately female volunteers can be effective in promoting health care in countries like Sri Lanka where a preponderance of educated youth live. (KC)