Feeding practices have been analyzed prospectively in a sample of 1,112 healthy infants selected from families using an HMO. Data were collected at well-child visits during the first year of life regarding breast-feeding, formula feeding, and use of solid foods and cow's milk. Seventy percent of all infants were breast-fed, with the mean duration of breast-feeding being almost 7 months. Factors positively associated with breast-feeding included education and marriage, whereas maternal employment outside the home and ethnicity (being Hispanic rather than Anglo-American) were related to bottle feeding. Solid foods were introduced earlier by Hispanics and, also, among less well educated and single women; maternal employment was unrelated to the introduction of solid foods. Multiple regression analysis indicated different patterns for the two ethnic groups: education and employment were related to almost all feeding practices for Anglo-Americans, whereas education and employment predicted few feeding practices for the Hispanics. These findings suggest that the effects of ethnicity are independent of those of education.