This study explores how teachers experience an online course designed to provide a situated approach to developing understanding of online learning. It describes how the course designer aimed to exploit the potentials of online tasks and interactions in relation to a rationale for situated teacher development, and then explores evidence of how teachers engaged with these processes. A picture of teacher engagement with the course mechanisms emerges from the teachers' own reflections on their experience. Findings suggest that online learning provided for situated opportunities for reflection in and on action. However, the ways in which teachers engaged with and experienced the course were varied, these being accounted for by individual characteristics such as cultural background, by teacher understandings of themselves as learners and online participants, and by individual responses to specific course attributes. The research contributes to understandings of teacher learning in online courses. (Contains 4 figures.)