Purpose: The development of the Amazon region shall be based on the sustainable exploitation of natural resources, avoiding great interventions on the primary forest and making efforts to restore the original vegetation in degraded lands. Extractivism is the main economic activity in the region and it can be the way to assure the use, conservation and recovery of natural resources. One of the most exploited is wood. In order to maintain its availability, forest management is implemented as a practice to obtain logs with least possible intervention. In this context, this study aims to evaluate the impacts caused by forest management in Amazonian rainforest. Methods: The study was conducted following the principles of the international standard ISO 14044 - Environmental Management - Life Cycle Assessment - Requirements and guidelines. This is a cradle-to-gate study, from forest environment to the gate of a sawmill. The system function is to provide log to sawmills and the functional unity is 35,500 Kg of log, that refers to the maximum of roundwood that can be extracted from one hectare of Amazonian rainforest (30 m3). The system is based in the state of Pará, in the north of Brazil, the greatest producer of roundwood from extractivism. The data refer to 2009 and the cycle of forest management is 30 years, it means that one hectare is exploited one time every 30 years. Six impact categories were evaluated: Acidification, Eutrophication, Global Warming, Photochemical Ozone Creation, Freshwater Ecotoxicity and Human Toxicity. Results: Log transportation and Diesel production were the subsystems with the highest contribution to the potential impacts. Clearcutting for roads and storage yards construction has a great influence in global warming. Conclusions: As the most important input, diesel plays a crucial role. Log transportation is the most important process to almost all impact categories. It should be given special attention to clearcutting for roads and storage yar