Life Cycle Assessment (LCA) is the most used methodology to assess the environmental impacts of supply chains. Despite being the most used methodology, LCAs studies regarding forest wood supply chains considering an exhaustive Life Cycle Impact Assessment (LCIA) approach are still lacking with the majority choosing a small subset of impact categories and indicators. This work aims to develop a comprehensive Life Cycle Assessment considering two different LCIA methodologies (IMPACT 2002 + and ReCiPe 2008) to the pulp and paper supply chain to identify possible alternatives that would allow a better environmental impact based on the identification of the most critical impact categories through the Pareto principle. A Portuguese company from the pulp and paper industry is used as an illustrative case study.