In the public health community, there is often a lack of research on implementation of interventions of known effectiveness. Challenges of implementation and gender and household dynamics that affect intervention uptake, are potential reasons why individuals fail to make behavioral changes that improve maternal and child health and nutrition. This research concerns a small-scale implementation research study within a larger five-year program, "Addressing Stunting in Tanzania Early (ASTUTE)", aimed at reducing childhood malnutrition at scale and preventing stunting in children, as stunting remains a serious public health problem among children under 5 in Tanzania. ASTUTE relied on community health workers (CHWs) to implement a significant portion of community-based programming in 5 regions of Tanzania. This research examined what factors affect CHW delivery of community interpersonal communication programs, and gender dynamics that affect the practice of behaviors promoted by the CHWs during home visits. This was assessed through the following aims: 1) Phase A: To assess who the CHWs are visiting for home visits, and if they are capturing the most vulnerable households, 2) Phase B: To understand how household gender dynamics, particularly decision-making, are associated with recommended of maternal and child nutrition behaviors, particularly behaviors that were promoted during the CHW home visit. In Phase A, we found low coverage of and many practical and legitimate barriers to providing home visits to the most vulnerable households, even by CHWs who were highly motivated. This research has implications for social and behavioral change (SBC) interventions replying on CHWs or other volunteers for community programs. In Phase B, our in-depth qualitative work allowed us to provide a deeper understanding on how perceptions of decision-making differ between men and women, how disagreement between couples affects decisions around food and nutrition, and lastly the role of intimate partner violence (IPV) in decision-making. Phase B highlighted the importance of gender transformative work, as well as considerations for measurement of household decision-making in behavioral change interventions. This mixed-methods dissertation uniquely identified understudied areas for improvement and scale up of similar community-based maternal and child nutrition interventions.