The political and economic agenda of the 21st century has called for greater alignment with the principles of Sustainable Development. Thus, using the extra-fiscal function of Brazilian taxes to achieve purposes that stimulate or restrain behavior effectively achieves the purposes of our Federal Constitution. This book will analyze the participation of municipalities in the distribution of the so-called "ICMS-Ecológico", a sustainable public policy instrument with a very positive impact on raising awareness of the urgent need for changes in socio-environmental priorities.