This study explored the professional development experiences of 28 practicing teachers in ten Chicago suburban schools involved in a two-Year technology supported Problem-Based Learning curriculum development effort. Asynchronous computer-mediated communications (CMC) were featured as teacher communication tools of the project. The computer-mediated discourse produced by the teachers was compared with the discourse produced by teachers in face-to-face meetings. Research methods including discourse and archival data analysis were applied to determine the nature of the teacher discourse and its reflective content. The results show that while the computer-mediated teacher dialogue was less interactive, it was significantly, more reflective (t = 4.14, p = .001) suggesting that the value of computer-mediated communication lies in its ability to facilitate professional collaboration between teachers and encourage critical reflection on educational policy and practice.