Moral autonomy is a concept drawn from moral philosophy that can help build an understanding of the ethical dimension of human resource (HR) managers' roles. In this article I suggest that the concept be used to avoid simplistically viewing HR managers as either irrelevant to the ethics of human resource management (HRM) or capable of guaranteeing moral HR practices. Drawing on the findings of a qualitative study I argue that HR managers face 'relative' moral autonomy. While their capacity to ensure decency in the management of human recourses is inevitably constrained, we must not assume away the possibility that they can be important moral actors who play a role in, and have a responsibility for, determining how ethical HRM is in any organization. Moreover, this capacity should be fostered by the HR profession and academic commentators given the growing decollectivization and decentralization of employment relations in Australia.