The conventional ways that new pedagogies are taught and supported in low- and middle-income countries rarely leverage the social networks and relationships that are paramount for individuals to shift their beliefs and make positive decisions about adopting new methodologies, and for them to sustain these behavior changes in the long run. The purpose of this study was to apply social network analysis (SNA) and qualitative inquiry to understand the composition and structure of primary school teacher social networks to inform policy basic education programming about how to improve the diffusion and support for implementation of new pedagogies through these social networks. This study used a mixed model design to study the compositional and structural properties of teacher social networks in sub-district administrative areas or “wards” in Tanzania. Using data from completed socio-metric inventories, separate teacher social networks were generated for Mbawala, Madimba, Milangominne, and Nitekela wards in the Mtwara Region of Tanzania. Researchers used SNA to calculate quantitative measurements and generate teacher sociograms (i.e., network graphs) for each of the ward-level teacher social networks. We combined these data with data from teacher informant interviews that described the content, context, and benefit of educators’ interactions in the different wards and to help explain the SNA findings.