Nationally, there is growing public interest in and policy pressure for developing alternative and renewable sources of energy. Wind energy facilities in the Pacific Northwest expanded rapidly over the past decade, as a result of state policies that encourage wind energy development. While much of the development thus far has occurred on private lands, there is interest in expanding onto federal land. However, there are concerns about the impacts of wind energy on wildlife. Wind energy facilities have the potential to harm wildlife both directly through collisions with turbines and transmission lines, and indirectly by modifying habitat. This report synthesizes the available scientific literature on potential wind energy facility impacts to wildlife, with a focus on the Pacific Northwest (Oregon and Washington), and summarizes the current best management practices recommended in federal and state guidelines for wind energy development. Research gaps in our understanding of wind energy impacts on wildlife remain. Future research needs include long-term, multisite, experimental studies of wind energy impacts on wildlife, improved ability to estimate population-level and cumulative impacts of wind energy facilities on wildlife, and better knowledge of key wildlife species’ migration and demography.