Infants of parents with a history of asthma could benefit from exclusive breastfeeding during the first 6 months of life to reduce the chance of developing childhood asthma. Continuing to breastfeed for 6 months seemed difficult to perform for many Dutch women. Therefore, an educational breastfeeding program was developed and implemented. The program (a theory-based booklet and pre- and postnatal home visits by trained assistants) significantly improved exclusive breastfeeding rates at 6 months postpartum (48% for intervention vs. 27% for control). Repeated-measurements analyses showed significant increases in knowledge and more positive attitudinal beliefs regarding breastfeeding for 6 months, in particular immediately after exposure to the program, compared with the controls. As expected, over time perceived self-efficacy and women's positive emotions toward breastfeeding increased, and support for breastfeeding diminished in both groups. The intervention group was reported to perceive more pressure to bottle feed and to know more breastfeeding models than the control group. Implications for practice are discussed.