In the student teaching triad model adopted in this study, pairs of pre-service teachers worked collaboratively with cooperating teachers during a 12-week field experience. The main objectives of the study were to document the benefits and challenges for pre-service teachers and cooperating teachers who participate in a triad model and to describe the co-teaching models that would emerge during this experience. Pre-service teachers and their cooperating teachers reported several strengths of the triad model in the following areas--learning from each other, professional support, outcomes for K-12 students, comprehensive feedback about teaching and classroom practice, and pre-service teacher confidence. Limitations and concerns identified by both groups included dependency, confusion with classroom management issues, loss of individuality, and competition between the pre-service teachers.