During a negotiation, there is seldom the time or capacity for parties to reach a full and complete agreement on a comprehensive legal framework for postconflict governance. Instead, the parties often agree to a preliminary set of principles coupled with a general governing framework.They then set forth an agreed process for negotiating, designing, and implementing a national dialogue, the drafting or amending of a constitution, and elections. This chapter explores the puzzle of whether and how to address constitutional modification during peace negotiations in a manner that promotes a durable peace. It reviews the peace processes related to conflicts in Bosnia and Herzegovina, Colombia, East Timor, Guatemala, Iraq, Kosovo, Macedonia, Nepal, Northern Ireland, Somalia, South Africa, Syria, and Yemen to explore whether and how to address constitutional modification during the peace process; the timing of determining and executing a postconflict constitution-drafting process; whether to draft an interim constitution; whether to accomplish constitutional reform through amendments or by drafting a full constitution; how to approve and finalize constitutional modifications; and whether and how to incorporate issues of human rights.