We prospectively investigated the weaning practices and fertility and birth control patterns of 95 educated, middle-class, urban-suburban, married, North American women in the year after the birth of their first child. Mothers recruited from childbirth classes responded to questions about their infant feeding and contraceptive practices during that year. Eighty-nine percent (n = 85) of the infants were initially breast fed, and the mean age of weaning for the 63 infants who had been weaned by 58 weeks was 26.9 weeks. The pattern of weaning was described, including the introduction of solid foods, food-related infant illness, and reasons for weaning. Although 70 percent of the mothers reported using artificial contraception, their fertility rate was higher than that reported for third-world women using only breast feeding as conception control. The data suggest that later weaning, even in this relatively affluent group, may result in direct contraceptive and physical benefits to the health of women and infants. The findings also suggest that the influence of health care practitioners on infant feeding practices may be as great as the influence of cultural values or material resources.