In Sub-Saharan Africa, prevention of HIV pediatric infection due to breastfeeding requires turning to alternatives to prolonged breastfeeding: artificial feeding or exclusive breastfeeding with early weaning. Choosing a preventive option and applying it does not only depend upon the mother but also on the father and more specifically on couple interactions. To date, not enough studies have considered this question. In Abidjan, Ivory Coast, HIV-positive women and their infants were followed over two years in Ditrame Plus, a prevention of mother-to-child transmission (PMTCT) project. Using data from this project and from interviews conducted with couples and women, we analyzed the construction of decisions and practices concerning the application of preventive infant feeding options. Differences may be found between women and men in discourses regarding their attitudes, which are in part related to their conceptions of motherhood and fatherhood. We found that when men know their wife is HIV positive and are involved in the PMTCT project, they play an active role in applying the advice received. However, women do not always need the support of their spouse to undertake preventative behaviour. The project team also plays an important role in the adoption of such by women and men. The implementation of preventive options is a complex process in which three groups of actors (women, men and the project team) interact. In order to optimize PMTCT programs for couples, it is essential that this dynamic be taken into account.