This monograph on biological diversity was prepared in order to update the data from the first monograph written in 1999. It reviews the current state of knowledge on biological diversity and describes the essential factors that more or less influence its evolution as well as the efforts undertaken by actors for its conservation and sustainable use. A total of twenty-four (24) themes were studied in order to obtain data dealing with various issues affecting almost all taxa and development sectors that impact the state of biological diversity in Burkina Faso. The current state of biological diversity in the country is marked by strong human pressure, which is mainly manifested by bush fires, swash-and-burn cultivation, overexploitation of resources, overgrazing, etc. In addition, the harmful effects of climate change are added.