Critical Friends Groups (CFGs) were established in 1995 as a form of professional development for teachers. The current study employed the use of video as a medium for documenting the effects of CFG participation on teaching practices. This allowed links to be drawn between CFG participation and teaching practice, a critical gap in the literature. This qualitative case study drew upon Knowles’s Adult Learning Theory to help provide a framework for thinking about Critical Friends Groups and analyzing the findings. The 9 participants in this study included 1 third grade Early Intervention Program teacher and 8 CFG members from an urban elementary school. Multiple data sources were analyzed including classroom teaching practice videos, focal teacher's and CFG members’ written reflections, CFG meeting verbatim transcriptions, focal teacher and CFG member interviews, and researcher memos. Data analysis was iterative and axial coding led to a code book depicting the final 6 key themes: change in teacher attitude toward the use of video, shared teaching practice, pedagogical-driven conversations, change in pupil engagement, captured classroom practice and promotion of teacher reflection. Barriers to the use of video in a CFG included logistics and teacher resistance. The researcher used data triangulation, member-checking and an audit trail to assure the trustworthiness of the study. Teachers reported that they learned from watching one another’s practices and from discussing each other’s ideas. The use of video in this study appeared to offer a viable innovation in an already prevalent model of professional development, CFGs. Video appeared to have much potential at the in-service level as it helped to cultivate knowledge, skills, and attitudes among teachers.