In March 1996, representatives from several Peruvian cities, grassroots organizations and NGOs, together with scientists and staff from universities and local government authorities, decided to establish a national forum to promote the development and implementation of Agenda 21 in cities in Peru. This came to be called the “Cities for Life” Forum which, today, brings together representatives from 41 institutions in 18 cities. This paper describes the origin and early development of the Forum - and its vision, strategies and work to date. It seeks to show how this Forum developed beyond what was initially a conventional project which depended upon technical assistance and the initiatives of a local NGO into a network of many different actors from many urban centres in Peru who, together, form an autonomous and independent entity. The Forum has encouraged and supported its members in developing and implementing local environmental action plans and in learning from each other’s experiences. The paper also outlines the main environmental problems in Peru’s urban areas and the unsupportive national framework within which urban authorities and other urban actors strive to address environmental problems.