The fact that civil society groups play important roles in post-conflict peacebuilding has entered the mainstream of international conflict resolution dogma. Rarely do local civil society groups get a seat at the negotiation table for peace accords. Although the exclusion of civil society from peace negotiations may streamline the process, the absence of civil society voices and interests at the negotiating table can negatively impact the sustainability of a peace agreement during peacebuilding. Surveying a wide variety of different peace processes, a strong correlation was found between active civil society participation in peace negotiations and the durability of peace during the peacebuilding phase. Cases in which civil society groups actively engaged in peace negotiations seemed to enjoy more sustained peace in the peacebuilding phase. This holds true also for cases in which civil society groups did not have a direct seat at the table, but did exercise significant influence with the negotiators because they were democratic actors. War resumed in many cases not characterized by direct or indirect civil society involvement in the peace negotiations. No claim of causality is made; the sustainability of peace surely rests on causes as complex and dynamic as the initiation of war does. However, these findings do call attention to the need for further research to understand the special impact that civil society inclusion at the peace table may have.