Bird-window collisions are a major cause of bird mortality in the world; up to one billion birds die each year from collisions with glass panes in North America alone.However, relatively little attention had been given to this issue in the broad scientifi c literature, despite a recent increase in the number of papers. In this paper, the indexed literature on bird-window collisions was reviewed, specifi cally addressing the causal factors. The search retrieved 53 papers, mostly from North America. The factors linked to higher collision rates were large areas of continuous glass, the presence of nearby vegetation and feeders, bird migration, abundance, and behavior. Several factors were site-specifi c, preventing the global extrapolation of these fi ndings. There is a lack of scientifi c knowledge regarding bird-window collisions in tropical countries. One of the challenges to mitigating this problem is the small amount of information andfrequently -the extrapolation of fi ndings described for temperate regions to other areas.There is a need for a greater and urgent effort to fi ll this gap.LGB and AJP conceived the idea designed the studies; LGB, DJM and AJP collected and analyzed data; all the authors wrote the manuscript and approved the final version.