The subject of justice and accountability raises significant challenges in peace mediation contexts, as well as in the implementation phase following a peace agreement. These challenges usually cannot be avoided and simply must be worked through. However, there are steps that the United Nations can take so that its staff and representatives are in a stronger position to plan, to respond to the substantive questions that arise and to better coordinate with each other. This paper sets out some of these challenges, and offers both policy and strategy ideas for addressing them.