Background: Return to work is often cited as a reason for early cessation of breastfeeding (BF). Our objectives were to study the time span during which women employed prior to pregnancy returned to work according to BF duration category, and to identify sociodemographic, behavioral and pregnancy characteristics of women who continued BF after returning to work. Methods: Information on BF mode and work status was prospectively collected in a French nationwide birth cohort up to 1 year after delivery. Time of return to work according to BF category was addressed using Kaplan-Meier curves and Poisson regression adjusted on co-variates. Multiple logistic regression enabled to identify characteristics associated with the combination of BF with work. Results: Among 2480 women holding jobs prior to pregnancy, 82.0% returned to work within a year postpartum. Women who breastfed > 4 months returned at median of 6.5 months, whereas those who did not breastfeed at all returned to their jobs at 4.0 months, those who had breastfed for less than 1 month returned at 4.5 months, and those who had breastfed for 1 to 4 months returned at 4.0 months. Around one-third of women (34.5%) combined BF and work, and breastfed for a longer duration (median: 213 days, vs. 61 days for women who stopped BF before returning to work). Women born outside of France or who were self-employed were more likely to combine BF and work, while intermediate employees, manual workers, women who quitted smoking during pregnancy, who had smoked before and during pregnancy, or who had given birth by cesarean section were less likely to combine BF and work. Conclusion: Women who had breastfed for less than 4 months, or not at all, returned to their jobs at comparable times. This suggests that working women should be encouraged to breastfeed, even for a short duration. Moreover, only one-third of working women succeeded in combining BF and work, highlighting the need for a support system that would encourage flexibility.