This article explores how critical conversations engage undergraduate mathematics faculty in a community of practice that enhances their knowledge about teaching and learning mathematics for social justice. More broadly, critical conversations are defined as a cooperative learning strategy that can be used to identify, explore, and respond to various interests and issues situated across differing values and beliefs. We present a case study of a critical conversation that took place at a 2016 Mathematics for Social Justice workshop organized by a group of junior faculty. Participant reflections situate perspectives that can help novice and experienced instructors design conversations about teaching mathematics for social justice. Specifically, individual and group reflections highlight the importance of: (i) framing and reflecting on the conversation; (ii) exploring implications and content connections; and (iii) identifying barriers. Implications for faculty members and mathematics departments are provided.