Military training areas (MTAs) are special environments with specific anthropogenic activities. The aims of this review are (1) to understand the interactions between military training activities and biodiversity, (2) to quantify the available scientific literature on this subject, (3) and to highlight the origin of the studies. Queries were carried out on two literature databases: Scopus and Wiley. The queries returned a large number of papers, but few actually matched the research topics. These two databases contain nearly 400 articles that discuss the interactions between military training and biodiversity at different scales. These articles come from all over the world, but the majority were conducted in the United States. In Europe, the studies are mainly conducted on German, English, and Czech sites. Impacts on biodiversity from all types of military training and from restricted areas were studied. The impacts on these areas are multiple and affect the landscape, the soil, fauna, and flora. They can be directly or indirectly related to military activities. Responses to disturbance by military trainings can be complex as they are variable. Thus, the same training may result in positive, neutral, or negative impacts depending on the habitats or taxa targeted and the country studied. Training methods are constantly evolving and vary between countries, and it appears important to maintain research about conservation in those particular areas, which paradoxically represent opportunities for nature conservation.