V Conferencia Internacional de ISTR, 7-10 julio, 2002, Ciudad del Cabo, Sudáfrica. In the past 15 years, Mexico has lived through intense social, political and economic change. This is reflected in the opening of markets, in the insertion into the globalization process, in the modernization of the governmental apparatus and just recently, in access to a new and different democratic political system. One could assume that these changes will eventually enable the country to provide better living conditions that will pave the path out of poverty, and social inequity that include more than 50% of the population. A strong presence and influence of civil society organizations (CSO) has been felt during this series of conflicts and tensions. Their visibility has grown in the public eye and on many occasions they have been the initiators and facilitators of these processes. This sector of society has not only played an important role, but also continues to accompany change as it occurs. Actually, these CSO have been claimed to be a reference of governance and decided promoters of the basis to extend citizens’ social, economic and political rights. During all these years this sector has also undergone important internal transformations which reflect on relationships with the market and the state. There has been a self examination of purpose and self identification undertaking various names: Non-profit sector, Third sector or NGO sector. They have overcome redefinitions, professionalization and some have met the challenge of sustainability. External modifications have been to initiate and continue a dialogue with the state and more recently, with the market. There has been a redefining not only of terms, but also of actions to be taken on all sides. Citizen participation and voluntary action have been rediscovered. The elections proved that changes are possible when there exists a collective will for it to occur. CSO have sprung up in the past decade as new voices try to be heard and new actions are needed. This paper will present what has been said in the dialogues with the government during this transition, providing examples and case studies of institutions and relevant CSO that have contributed with models of new relationships demonstrating how these have enabled social change in Mexico. It will also present the changes in relationships and structures of voluntary action under the new regime, including the latest studies and comparative volunteer surveys to date as to provide more accurate information about voluntarism and citizen participation in Mexico.