This work assesses the role of civil society groups in peace building in South Sudan after the signing of Comprehensive Peace Agreement (CPA). More specifically, it seeks to assess the role of civil society on service delivery, rights advocacy & protection of citizens in peace building in South Sudan after signing of the CPA, as well as to determine the effectiveness of civil society in implementing its rights promotion and peace building mandates. The results indicate that the civil society played an important & effective role in peace building in South Sudan during conflict, & contributed positively to the peace building process. Civil society groups in South Sudan have contributed to the reduction of violence, negotiation of settlements & the facilitation of peace after signing of the CPA. Service delivery as such is seen as an economic task of the state, the market or the third sector. But, service delivery is connected to the civil society, as many of its actors have taken up service delivery parallel or alternatively to the state or the market. Service delivery, may also be seen as a civil society function when directly linked to other civil society functions or aims.