Acute lateral ankle sprain (ALAS) is one of the most frequent musculoskeletal injuries, with a great impact on health and socioeconomic factors. There are few consensuses on this subject and multiple therapeutic options that are difficult to compare due to the lack of a universally adopted classification system. The objective of this study is to is to report the actual knowledge on how ALAS are classified and reported and not to make any therapeutic recommendation. A comprehensive literature review of the literature was carried out through a search in the MEDLINE, Cochrane Library and Google Scholar databases, with identification of articles that describe ways to classify lateral ankle sprains or with relevant content for their classification. Twenty-five different classification systems were identified. The majority of articles referring to ALAS use an unspecific classification. Most classification systems divide sprains into 3 degrees. The most used parameters are the anatomy of the injury, clinical parameters, functional loss and the presence of instability. No articles were found to verify the validity of the systems used, namely regarding their association with therapeutic proposals or prognostic predictions. Based on the available evidence, recommendations cannot be made regarding the most appropriate classification system. The considerable heterogeneity of the existing literature makes it difficult to compare studies and to optimize the treatment and follow-up of these injuries. Future research in this area is necessary to define a practical and rigorous system that can be used universally.