This mixed-methods study employed Hargreaves and Fullan's (Professional capital: transforming teaching in every school, Teachers College Press, New York, 2012) concept of professional capital to re-examine whether professional learning communities (PLCs) transformed instructional practices in contexts that endorse hierarchical cultures. PLCs that facilitate transformational change in instructional practices empower teachers to embrace ambiguity, conflict, and risk to improve both student and teacher development. In contrast, PLCs that disseminate instructions for implementation produce reifying change. The findings illustrated that, in Singapore's hierarchical cultural context, teachers participating in PLCs with high professional capital demonstrated transformational practice. These PLCs differed from most others in teacher cultural disposition toward uncertainty, unequal relationships, and risk. The findings imply that PLCs have the potential to support transformational change in practice, even when the cultural context endorses hierarchical relationships. However, this potential is moderated by the teacher cultural dispositions that prevail in PLCs. PLCs that possessed medium professional capital were the majority, demonstrating efforts to reify instructional change. Low professional capital PLCs also differed in teacher cultural disposition from the middle majority, but demonstrated neither the transformational practices of high professional capital PLCs, nor the reifying practices of medium professional capital PLCs. Recommendations are given in this paper to PLCs situated in similar hierarchical cultures on the types of adjustments required to support transformational change in practice.