This work consists in an analysis about the main challenges faced by the mechanisms of participatory democracy in order to assure the right to the city in places impacted by large economic projects implemented on Amazon. The object are cities that appeared and developed themselves in a sudden way, in the context of an intense urbanization process boosted by the advance of capitalism on that place, trying to exploit natural resources, which resulted in urban places characterized by precariousness and by inequality, imposing enormous obstacles to the effectiveness of urban laws. Beside one wide reading of works and studies regarding to the main theoretical aspects involved, both to the reality of urban places on the Amazon and to the economic enterprise happening on that place, we produced an empirical research that chose 02 (two) cities characterized by the main aspects of this current urban phenomenon (Parauapebas, on Pará State, that is developing itself under the influence of Grande Projeto Carajás of the Vale Company and Laranjal do Jari, on the Amapá State, that is developing itself under the influence of Projeto Jari). Thus, the focus is the east territory of that region to measure the difficulties imposed during the period comprised between 2001 to 2011. The analysis starts from a theoretical and conceptual discussion about the right to the city and participatory democracy, tracks a brief course of the main processes of development boosted on the region, highlighting both the state action as its inducer and the particularities of the resulting urbanization, discusses the unfolding of some large economic projects implemented on those cities and its relationship to the respective urban shaping, searches to measure the effectiveness of its main urban laws and, ultimately, it analyzes the main challenges that the mechanisms of participatory democracy are facing to assure the right to the city. It was possible to conclude that the conceptual classic aspects regarding that theme needs to consider both the particularities of that place and its urbanization process in order to better understand that phenomenon and, mainly, that the biggest challenges imposed on the laws are resulting from the action of economic and conservative sectors focused on the maintenance of their interests, that the local government is weakened, with small possibility of enforcing the collective interests and that the particularities of the urbanization process on the region amplify the difficulties faced.