This paper describes the integration of cooperative learning (CL) activities into a graduate teacher education course, Collaborative Teaching in English as a Second Language (ESL). Because teachers and researchers have both identified discipline status and relationship issues as challenges to collaboration, this course focused on relational dynamics such as respect, trust, reciprocity, and approachability as central to the successful implementation of collaborative practice. CL activities were integrated into the program to encourage ESL teachers to explore their own values and expectations for learning as well as their own communication styles which might facilitate or hinder collegiality. The research question asks how CL contributes to teachers' understanding of themselves as communicators, collaborators, and agents of change. From a qualitative analysis of observer notes, journal entries, classroom discussions, group activities, and autobiographies, this paper highlights how dimensions of CL can be used not only as methodology in second-language teacher education but also as a model for developing collaborative relationships between ESL and content-area teachers. (Contains 1 table.)