ABSTRACT There is a growing interest in the role of individual mission leaders in UN peace operations in peacekeeping studies. However, the concept of ‘agency’ has remained latent in much of this literature. This omission presents a risk of concept stretching and concept ambiguity as scholars continue to explore this topic. In this paper, I analyse the different ways in which the agency of mission leaders has been (implicitly) conceptualized thus far and argue that the existing literature pays insufficient attention to how the scope for individual agency can be context-dependent. Furthermore, I contend that mission leaders are too rarely seen as real human beings, with personalities, background experiences and values. I build on sociological and principal/agent-theories to develop the concept of ‘personal identity’ and then formulate a set of conditions under which the room for individual agency in UN peace operations is enhanced or reduced. Subsequently, I demonstrate the added value of this approach by conducting an illustrative case study of Patrick Cammaert’s tenure as Commander of MONUC’s Eastern Division between 2005-2007. The article shows that investigating the interaction between structure and real-world agents leads to a more holistic and sophisticated understanding of the behaviour of peacekeeping leadership.