BACKGROUND: Human breastmilk is considered the ideal form of infant nutrition. The American Academy of Pediatrics and the World Health Organization officials recommend breastfeeding exclusively for the first six months of life and continued breastfeeding for at least the first year of life. Despite these recommendations and increased promotion of exclusive breastfeeding through six months by the American Academy of Pediatrics and the Centers for Disease Control, new mothers living in rural U.S. communities have lower incidence of breastfeeding as compared to their urban counterparts. Little is known about the experience that fosters success or failure to exclusively breastfeed to six months. PURPOSE: The purpose of this study was to develop a substantive theory that describes the decision-making process for women in a rural population to exclusively breastfeed. Decision-making did not emerge as a construct by participants of the study. METHODS: Nineteen participants who reported a desire to exclusively breastfeed were recruited using both purposive and theoretical sampling. The research employed classic grounded theory method to understand the meaning and experiences of exclusive breastfeeding. FINDINGS: The theory of seeking to do what's best for baby emerged from the data. It consists of a temporal three-stage process. The stages are 1) pre-pregnancy nescience, 2) working through, and 3) succeeding or surrendering. The process is influenced by evolving internal conditions identified as enculturating, believing, and lacking knowledge. Also identified are basic social processes and conditions that influence the core category of working through and affect the three-stage process. The basic social psychological processes that impact working through are struggling, needing support, winging it, and admitting fed is best. The basic social structural processes that impact the core category of working through are health care, family structure, customs, hierarchy, and social media. CONCLUSIONS: The theory seeking to do what's best for baby explores how rural mothers attempting to exclusively breastfeed for the first six months, navigate the basic social processes encountered and resolve their main concern of doing what is best for their baby. The theory is supported by both the theory of planned behavior and symbolic interactionism. This new grounded theory has pertinent implications for research, nursing and clinical practice, breastfeeding policy, and education that may promote healthy outcomes for infants living in rural communities.