The use of an online learning community is one possible approach to teachers' professional development that can enhance the opportunity for collaboration. Discussions in online learning communities not only allow community members to share resources, ideas and expertise, but also contribute to the fulfilment of teachers' needs in terms of continuous learning and professional development. This paper reports the findings of a study that aimed to explore the factors that influence the way teachers behave in online communities. The research participants were 16 teachers from five secondary schools in Malaysia who were teaching English, science and mathematics. These teachers were involved in online learning communities via blogs in which they exchanged stories and experiences related to their teaching and learning activities. Data were generated through one-to-one interviews. Based on thematic analysis, the overall findings indicate that teachers' levels of participation in their online learning communities were largely influenced by cultural issues. Other factors that impacted upon their engagement were time, enforcement by school administrators and their need for an online community.