When should peacekeepers partially or fully withdraw from a country or region in which they are operating? This important question has received little scholarly attention. However, it has profound implications. If peacekeepers depart prematurely, as happened in Rwanda in 1994, the consequences can be disastrous with the potential to lead to widespread preventable deaths and human suffering. If they overstay, peacekeepers risk alienating the population they are seeking to protect and undercutting popular sovereignty at significant economic costs. Striking a balance, we propose a framework for just withdrawal that is both normatively compelling and empirically sound. It focuses on three aspects that are vital for understanding when peacekeepers can depart in an ethically justified manner: just cause, effectiveness, and legitimacy. By considering a number of objections, we also address critics who challenge the overarching premise of peacekeeping or might prefer different standards by which to suggest peacekeepers should stay or depart. Finally, we illustrate our argument with theoretical and empirical examples and a discussion of UN peacekeeping in East Timor.