While the literature on professional learning communities (PLCs) has proliferated, much of it derived from and contextualised in Anglo-American settings, the concept and practice of PLCs in Asian contexts of strong hierarchies have largely been ignored. Based on literature and documentary analysis, this paper investigates the systemic implementation of PLCs in Singapore schools. The authors seek to show first how policy developments have in effect been laying the seedbed for PLCs for some 13 years, and yet evidence suggests that teacher pedagogy has been slow to change. Secondly, Singapore educational cultural and institutional contexts are reviewed to reveal how they mediate and filter "Western" notions of PLCs. Three potential implementation difficulties are identified--high teacher workloads, ambiguity of PLC processes and their efficacy, and hierarchical system and workplaces. Conclusions and implications emphasise the importance of effective school leadership in developing PLC practices, and how societal culture and context fundamentally shape the form that PLCs take.