Rapid population growth in developing countries, especially in urban areas, will produce an unprecedented sanitation crisis in the next century. A self-help latrine construction program initiated in 1976 by Mozambique's Ministry of Health offers important lessons for other African countries. Although thousands of latrines were constructed in low-income urban communities in a short time period, the campaign largely failed because of a lack of technical guidance in latrine design and construction and chronic shortages of appropriate building materials. In response, a research project was commissioned in 1979 to identify and develop a suitable technology and methodology for large-scale implementation of improved sanitation in peri-urban areas. This led, in turn, to creation in 1985 of the National Program for Low-Cost Sanitation funded by donors, the central government, and user communities. The technology is based on the concept of a simple, unreinforced domed concrete slab placed over a lined or unlined pit. Employment of community members in local production units enhanced poverty alleviation. Community members also served as animators, assessing the individual needs of those without sanitation, monitoring and evaluating program performance, and promoting hygienic behavior practices. Existing communication channels were used to publicize the program. Despite adverse economic and political conditions, 170,496 improved latrines were installed in 1979-96. The success of this program is attributed to the identification of a simple technological solution, affordability, and an integrated health and hygiene education package.