Patterns of infant feeding, based on cultural beliefs, affect the nutritional status, health, and growth of children. In order to understand malnutrition and infant health in a particular community, knowledge of both the beliefs and the practices associated with infant feeding in that community is essential. For this reason, it is critical that research strategies for collecting both traditional 'soft' data (the cultural context) and 'hard' data (observed patterns of infant feeding) be employed. A two-year study of infant feeding in Mali (1982-1983) provides detailed information about breastfeeding and weaning beliefs and practices. In this community, virtually all women breastfed their infants. Infants were nursed on demand, for comfort as well as nutrition. Weaning took place at an average age of 20.8 months, with a range of 6-32 months (N = 136). Bottle/formula use was very rare. Breastfeeding and weaning practices affected the growth and development of infants during the first two years of life. In contrast to many other populations, however, a number of infants in this community showed improved growth after weaning. Some traditional beliefs about infant feeding are changing under the pressure of urban norms, while others remain resistant to change, with varying effects on infant health.