An epidemiological survey in rural Tanzania indicated that the rate of trachoma was elevated in children whose faces were unclean. To aid in designing a health education program to increase face washing, a descriptive village study was done to determine water use patterns, attitudes towards face washing, responsibility for child hygiene, and decision making processes in the household and community. The study found that mothers were responsible for both water use and the health and cleanliness of the children. However, health education could not be directed at the women alone because the decision to change behavior had to be sanctioned by the husband in the household, and the community as a whole. The final health campaign was designed to be compatible with the accepted patterns of decision making. This case study, as well as others which focus on women's groups as change agents, suggests several factors such as male migration and local authority structures which health planners may need to assess when designing health programs.