This paper analyzes the regulation of cannabis in sports, with a particular emphasis on the justification for its prohibition among athletes. To fully understand the issue of cannabis in the context of sports, the history of cannabis use, its chemical components, and methods of consumption are first presented. The global legal regulation of cannabis, shift in public's opinion, and their impact on legal frameworks are briefly outlined. Doping in sports is a complex and controversial issue recognized as a significant threat to the integrity of sports competitions. The development of the fight against doping on a global level has resulted in the establishment of the World Anti-Doping Agency (WADA) and the creation of the World Anti-Doping Code, within which cannabis is listed as a prohibited substance. WADA's regulation of cannabis has undergone certain changes over the years, largely driven by new medical findings about the effects of cannabis and the demand from the sports world for the alignment of sports regulations with the evolving social and legal perception. Furthermore, WADA's criteria for their decision to prohibit consumption are presented, along with an analysis of their justification. Said is commented through examples from the sports world, including well-known cases of athletes who faced penalties for cannabis use. Finally, the paper also provides an overview of cannabis regulation in professional sports leagues in North America, such as the NFL, NBA, and NHL, and analyzes how these leagues have adapted to changes in societal attitudes and the current legal landscape. Different regulatory models and their consequences for athletes and sports are outlined. Through the analysis of legal and ethical aspects of cannabis regulation in sports, the paper provides a comprehensive overview of the current state and possible directions for future regulations, contributing to the discussion on the justification of current bans and encouraging further research and discussions on this topic.