Purpose: The aim of this study is to explore whether and to what degree community development of teacher teams takes place and how community development comes about, that is, what community-building efforts teacher teams undertake. Design/methodology/approach: Using a multi method approach, quantitative and qualitative data were gathered from seven interdisciplinary teacher teams in a secondary school during one school year. Teachers' perceptions of community development were complemented with video-observations of team meetings by relative outsiders. Findings: Data showed that the teacher teams undertook a wide variety and amount of community-building efforts. However, community development of the teacher teams as perceived by the teachers was limited. Relative outsiders observed some community development. Practical implications: From the findings the authors conclude that school managers could play a more proactive role in supporting teacher teams' community-building efforts. Strategies embedding community-building into the culture and policy of the school, including diagnosing, custom-made support and making efforts explicit, could be effective. Originality/value: The current study takes a long-term approach, investigating the community development of teacher teams during the course of one school year. In addition, community development is measured using two perspectives, i.e. that of the community members and that of the relative outsider. (Contains 5 tables and 1 figure.)