Infant mortality was chosen as an index of health status of an area of Mali where a primary health care program was being introduced. A survey of 811 mothers from the area was conducted to gather data concerning the deaths of children within the 3 years preceding the survey. This paper describes in detail the kinds of data solicited, including age and health of mother, age of child, and symptoms prior to death; and the coding, organization, and analysis of the data. Results are presented in tables and diagrams, and are judged to be valid and consistent with results obtained in other areas of West Africa. Tetanus resulting from severance of the umbilical cord was found to be a major cause of death in the first week after birth; action recommended is vaccination of mothers and improved child-birth conditions. Malaria was shown to be another key target, and while elimination of the disease is not yet feasible, chloroquin could be dispensed to young children. To fight gastroenteric complications and respiratory illnesses, also major causes of infant mortality, improvement of nutrition and sanitary conditions was indicated. Results also suggested that greater spacing of births would lower infant mortality rates.