Manage a soccer tournament can be a tedious task if it is done manually. This article presents the development of SIDUTSA, an on-line system based on decision trees, which allows the administration of the football tournaments to be automatic. By entering only, the participating teams and the results of the matches, the system organizes the matches automatically at each stage of the championship playoffs, quarter finals, semi finals and the final. SIDUTSA was developed using the language of Transact-SQL programming and a SQL server database manager. It is shown that it is possible to implement low-cost systems using efficient software architectures, easy to manage and potentially scalable. It was possible to develop software that allows you to: 1) automate the information corresponding to the management of soccer tournaments, 2) generate reports of the classification of the participating teams, 3) give independence to personnel in charge of the logistics, and 4) contributes to the decline in the use of paper. It is hoped that this tool can be used in other institutions that also carry out soccer tournaments.