Objectives: Using data from the ELFE study (French Longitudinal Study from Early Childhood), the primary objective of this study was to describe, using a large representative sample of births in metropolitan France in 2011, the total duration of breastfeeding (the period during which the child receives breast milk regardless of other foods or beverages consumed), and then to distinguish this from the duration of exclusive breastfeeding (the only milk received by the child is breast milk). The second objective was to identify the sociocultural, demographic, and economic factors associated with the duration of breastfeeding. Methods: The Elfe study follows more than 18,000 children born in 2011 in 320 randomly selected French maternity wards. Data on the child’s feeding were collected via an interview at birth, by telephone at 2 months and 1 year of age, and through a monthly self-administered questionnaire between 3 and 10 months of age. Bivariate linear regressions, performed on children who were breastfed (n=12,657), were used to test associations between duration of breastfeeding and sociocultural, demographic, and economic factors. Results: Among the 70% of mothers who initiated breastfeeding, the median total duration of breastfeeding was 17 weeks, and the median duration of exclusive breastfeeding was 7 weeks. Only 19% of children were still receiving breast milk at 6 months. Total duration of breastfeeding was shorter among mothers under 30 years of age, living alone, with a low level of education, or who returned to work less than 10 weeks after childbirth. In contrast, breastfeeding lasted longer among mothers in managerial positions (compared to employed mothers), those on parental leave (compared to those who were working), and those who had attended childbirth preparation classes. Breastfeeding also lasted longer when fathers were present at the birth. The factors associated with total duration of breastfeeding and the duration of exclusive breastfeeding were similar, with the exception of the parents’ country of birth and the father’s employment status. Conclusion: The duration of breastfeeding in France falls far short of the 6 months of exclusive breastfeeding recommended by the World Health Organization (children receiving only breast milk to the exclusion of any other beverage, including water). This initial analysis suggests that barriers to extended breastfeeding are associated with family circumstances, employment status, and factors related to education and culture.