As the global health agenda shifts from the Millennium Development Goals (MDGs) to Sustainable Development Goals (SDGs), the need for effective preventive health efforts has gained prominence, particularly in low-income regions with poor health and nutrition outcomes. To address needs in communities with limited access to health services and personnel, it is important to develop strategies that can improve the effectiveness of nurses as they interact with the populations they serve. We contribute to informing such strategies by explaining how mothers’ “reflective trust” in community health nurses develops as a key influencer in their health-related decision-making and behavior. Between December 2012 and June 2013, our ethnographic study gathered data in three adjacent rural and semi-rural communities in Ghana’s Eastern Region, using interviews with 39 nursing mothers, three focus groups – with mothers, health-workers, and community leaders – as well as 941 h of participant observation. We focused on interactions between mothers and nurses, highlighting tensions between communities’ traditions and messages that nurses bring, which are often based on modern science. We also investigated how mothers come to exhibit reflective trust in the nurses to make sense of traditional and scientific knowledge on infant feeding, and integrate them into their own feeding decisions. Our findings have global implications for effectively sustaining and scaling health and nutrition efforts through community approaches.