Peer-led dialogue groups (i.e., support or self-help groups) are a widely used community-based strategy to improve maternal and child health and nutrition. However, the experiences and motivation of peer educators who facilitate these groups are not well documented. We implemented eight father and ten grandmother peer dialogue groups in western Kenya to promote and support recommended maternal dietary and infant and young child feeding practices and sought to understand factors that influenced peer educator motivation. After four months of implementation, we conducted 17 in-depth interviews with peer educators as part of a process evaluation to understand their experiences as group facilitators as well as their motivation. We analyzed the interview transcripts thematically and then organized them by level: individual, family, peer dialogue group, organization, and community. Father and grandmother peer educators reported being motivated by multiple factors at the individual, family, dialogue group, and community levels, including increased knowledge, improved communication with their wives or daughters-in-law, increased respect and appreciation from their families, group members' positive changes in behavior, and increased recognition within their communities. This analysis also identified several organization-level factors that contributed to peer educator motivation, including clearly articulated responsibilities for peer educators; strong and consistent supportive supervision; opportunities for social support among peer educators; and working within the existing health system structure. Peer educator motivation affects performance and retention, which makes understanding and responding to their motivation essential for the successful implementation, sustainability, and scalability of community-based, peer-led nutrition interventions.