ABSTRACT Much of what peacekeepers do on a daily basis is best understood through the lens of practice, and practice theorists have begun to explore the process by which practice change occurs in international organizations. Yet practice theory’s focus on tacit knowledge and ‘unthinking’ action raises important questions about agency. How can individual peacekeepers change their daily practices amid the myriad structural factors that dispose them to act in particular ways? Do changes in peacekeeping practice require conscious reflection on their part? Drawing on evidence from UN missions in Sierra Leone, Côte d’Ivoire, and the DRC, I argue that changes in practice often occur through interpretive agency as individuals determine what rules require in practice. Interpretive agency takes two distinct forms: practical agency and reflective agency. Reflective agency involves conscious deliberation, while practical agency occurs when peacekeepers make unthinking adjustments to existing practices. This article identifies conditions that are conducive to each type of interpretive agency, highlighting the impact of crisis, bureaucratic hierarchy, and the role of specialized knowledge. These findings improve our understanding of how individual agency shapes UN peace operations, while also contributing to wider debates about change and continuity in global governance.