Blogging has been recommended as a suitable tool for teacher professional learning due to its associated utility in collaborative learning, reflection, communication, and social support. In this study, blogging was incorporated into a collaborative inquiry project involving elementary and secondary teachers. In examining the frequency and nature of blog usage as well as perceptions of blogging among the participants, a mixed-methods design was used. Quantitative and qualitative data sources included individual semi-structured teacher interviews, blog entries, and a blog statistics tracking tool. Results revealed that there are both benefits and challenges of using blogs to facilitate teacher collaborative inquiry. The participants in this study viewed the blog as a tool for facilitating the sharing of knowledge, teaching strategies, and assessment practices, as well as networking among colleagues. The blogs were more likely to benefit teachers who were shy, introverted, and reflective. Blogging also posed challenges for the teacher participants, including: low levels of perceived usefulness and perceived ease of use; lack or insufficient amount of in-service teacher training on using the blog; time limitations; technical problems; lack of immediacy and synchronous interactivity.