Research has extensively linked teacher collaborative work with opportunities for both explicit and implicit professional development. However, while teachers work together more often than before, little is known about how workplace collaborative contexts are structured in terms of who and how frames the problems of practice. Drawing on an ethnographically inspired case study, this article examines three common collaborative contexts and discusses how and why different ways of structuring them through problem framing mattered for professional development. The findings reveal that the context intended for school improvement offered only incidental opportunities for teachers to engage in problem framing. The 'work works' question was central in structuring the contexts intended for professional development and often acted as a limiting frame. In contrast, teachers' work with student cases involved broader opportunities for explorative problem framing. The analysis emphasises the role of framing questions in structuring teacher collaborative work.