This study aims to provide an overview of the health care system in specific regions of the Amazon, before and after the construction of Jirau Hydro Power Plant (HPP) to evaluate the efficiency of health activities planned and executed in the scope of the environmental licensing of the project. We studied the health conditions before the implantation of the project, identified the main characters and criteria involved on the definition of health issues and obligations assigned to the entrepreneur, as well as the results on heath inherent of those obligations, evaluated through qualitative and quantitative indicators, applied in different time cuts. The data used to define the quantitative indicators was obtained from the Municipal Health Department of the Municipality of Porto Velho and from heath units located in the studied region. As for the qualitative indicators, the data was obtained from structured questionnaires applied to part of the local population, users of the public health system.