Alessandra N Bazzano,1 Richard A Oberhelman,1 Kaitlin Storck Potts,1 Leah D Taub,1 Chivorn Var2 1Department of Global Community Health and Behavioral Sciences, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA; 2National Institute of Public Health, Tuol Kork, Phnom Penh, Cambodia Background: Appropriate and timely breastfeeding practices markedly improve lifelong health outcomes for newborns, children, and mothers. Exclusive breastfeeding is reported to be widely practiced in Cambodia, and important progress has been made toward achieving improved child health outcomes, but newborn mortality has been slow to reduce and breastfeeding practices remain suboptimal. Methods: Formative research was conducted in Takeo province, Cambodia to describe the practical, cultural, and social factors underlying current breastfeeding behaviors to inform the design of a newborn survival intervention that may improve breastfeeding. In-depth interviews, observations, a collection of visual media, and focus groups were employed to gather qualitative data. Results: The results revealed knowledge and practice gaps in behavior that likely contribute to breastfeeding barriers, particularly in the areas of infant latch, milk production, feeding frequency, and the use of breast milk substitutes. The predominant theme identified in the research was a dearth of detailed information, advice, and counseling for mothers beyond the message to exclusively breastfeed for 6 months. Conclusion: Future newborn survival interventions and postnatal care counseling in this area must go beyond the exclusive breastfeeding message. To achieve further impact, it will be necessary to disseminate comprehensive and locally appropriate information on breastfeeding and to improve counseling in order to support successful breastfeeding and to contribute to population-level health gains. Keywords: formative research, health education, lactation, behavior change, newborn