Although task-based teaching is frequently practiced in contemporary English language teaching, it is underresearched in state school settings. This article contributes to filling this gap in the literature by using qualitative case study data to explore how a task-based innovation was implemented in three primary school classrooms in Hong Kong. Analysis of classroom observation and interview data shows how the case study teachers reinterpreted a new curriculum in line with their own beliefs and the practical challenges occurring in their school contexts. Drawing on classroom episodes, the article highlights three issues that proved problematic when the tasks were implemented: use of the mother tongue, classroom management or discipline problems, and the quantity of target language produced. Implications for the design and implementation of task-based pedagogies in primary school contexts are discussed. (Contains 3 tables and 4 footnotes.)