The purpose of this study was to explore the potential value of online video case discussions among preservice and inservice teachers, and the video case teacher as a tool for the professional development of teachers. Participants included a total of 26 preservice and inservice mathematics teachers and a veteran teacher who appeared on the video case. Using content analysis techniques, we provided a thematic analysis of the teacher discourse and demonstrated the exchanges between the participating teachers and video case teacher. We also assessed the overall effectiveness of our online forum set up for the professional development of teachers. Results indicated that participant teachers were able to make theory-practice connections by articulating specific frameworks that guided our study. The inclusion of the video case teacher was beneficial for the other teachers in several ways. We contend that online forum discussions of video cases in which collective engagement of preservice and inservice teachers, and the case teacher have a great potential to support teacher professional development. (C) 2009 Elsevier Ltd. All rights reserved.