In this publication, Brazilian state capitals are describing cases of successful environmental projects in their municipalities, and hence, showing possibilities to organize a more sustainable and healthy way for cities to function. To exchange those ideas and to find possibilities to co-operate in areas where it makes sense, representatives of the departments of environment of these capitals met for a first national reunion in Rio de Janeiro on May 15th to 18th, 2012. Various representatives of the total 27 Brazilian state capitals signed a Charta to be handed over to the C40, group of the 40 biggest cities in the world, during the Rio +20 summit, to underline their will to improve intermunicipal co-operation and to keep working on sustainable and coherent policies.