The building of teacher networks or communities is increasingly seen as an alternative form of professional development, allowing teachers to share experience, information and good practice. The present article describes and analyses the activities of such a community, developed within the framework of a national debate, initiated to investigate the potential of online teacher communities in Cyprus. The study outlines how this community evolved on the basis of data collected through, firstly, records on the extent and the quality of contributions, and, secondly, telephone interviews with group members to reveal their own interpretations of participation. In light of an apparent failure of this online community to become a community of practice, factors contributing to this failure are further discussed. In particular, this study reflects on underlying issues, involving mostly the social infrastructure required for such communities to function efficiently and effectively. Such issues relate to enhancing participation, building identity and community, facing administration and facilitation concerns and addressing technical aspects.