Many studies have acknowledged that exclusive breastfeeding has a significant positive influence not only on babies but also on mothers, families, environments, and even nations. However, the rate of exclusive breastfeeding in the world has been low and this is also the case in Indonesia. Most studies in relation to breastfeeding focus on mothers as the influential factor for successful exclusive breastfeeding, and the variable of fathers tends to be neglected. In Indonesia, there is a fathers’ breastfeeding support community which was founded to raise breastfeeding awareness and highlight the importance of fathers’ values on breastfeeding practices. This qualitative study was undertaken in Jakarta and aimed to gain a better understanding of Indonesian fathers’ involvement during exclusive breastfeeding. Five main questions were addressed. Firstly, why and how fathers were involved during the exclusive breastfeeding period? Mothers’ perspective and experiences about fathers’ involvement were then explored. Then, whether fathers’ involvement in breastfeeding in Indonesia is seen as a non-traditional value and if so, how families managed it. Lastly, how the online advocacy group (Ayah ASI) for fathers could support exclusive breastfeeding. In-depth interviews were conducted to obtain data associated with the research questions. Since fathers’ involvement, explanations and experiences were the focus of this study, the main of source of information was Indonesian fathers. Additionally, mothers’ experiences and views, particularly the perspective of the wives of the fathers who were interviewed, were also considered to gain a comprehensive understanding of the involvement of their husbands. Information was also gained from the founders of AyahASI, the breastfeeding supporting community for fathers. Several insights were obtained by interviewing couples in Jakarta. The couples believe that exclusive breastfeeding has positive impacts on babies’ health and strengthens their bond with their mothers. In addition, religious factors encouraged fathers to support their wives to fulfill exclusive breastfeeding. The most significant findings were that fathers’ attributes influenced the success of exclusive breastfeeding and that psychological support by fathers of mothers is the most important factor in achieving exclusive breastfeeding. This research has revealed some important messages that should be addressed to increase exclusive breastfeeding rates in Indonesia. Even though the Government of Indonesia has released a policy to increase the exclusive breastfeeding rates, the implementation of this policy warrants further attention, for example providing more nursing rooms in public places. In addition, paternity leave should be considered as according to current regulations, the only leave available to fathers is two days. The fathers and mothers who participated in this research stressed that paternity leave was crucial in the early days after a baby’s birth to support mothers facing all the challenges in first months of their babies’ live. These recommendation are important means to enable fathers to become more involved with the care of their child. The more the fathers are involved, the more successful exclusive breastfeeding will be.