Wind energy had a remarkable growth in Portugal over the last 10 years. As it happened in other countries, several pre- and post-construction monitoring studies have been performed in order to assess the impacts of turbines on flying vertebrates. However, few studies gathered data collected at different sites and analysed it in an integrated way. As one of the first tasks of the R&D project, Wind & Biodiversity, this paper presents the results of the literature revision regarding bat and bird mortality at onshore wind farms. We were interested to know: 1) which species or assemblages present higher levels of mortality; and 2) when and where these events are more evident.