The author analyzed features of legal construction of the contract on the transfer of a professional athlete from one sports club to another (transfer contract). The author concludes that the transfer contract is a civil law contract, which mediates a sports club assignment of the claim to the athlete for the implementation of sports activities and participation in sports, in favor of another sports club, for the contract fee. At the present stage of national professional sports the conclusion of transfer contracts in Ukraine is actually illegal, as it breaks the law. The only possibility of legal and regulatory reasonable use of transfer contracts in Ukraine is the legal recognition of civil law relations arising between athletes and sports clubs about the implementation of sports activities and participation in sports with the possibility of contracting the provision of sports services (sports contracts).