Economic activity in Indonesia is growing rapidly. Economic activities are governed by the applicable constitutions and regulations, one of which is constitution No. 5 of 1999, on the Prohibition of Monopolistic Practices and Unfair Business Competition. Although there are regulations governing the Prohibition of Monopolistic Practices and Unfair Business Competition, the fact is that there are still problems regarding unfair business competition practiced by businesses. An example of unfair business practices is tender conspiracy, that can be found decision number 11/KPPU-L/2015. This study will analyze the verdict of the KPPU assembly and the sanctions placed upon businesses and other parties who are involved in tender conspiracies, as seen in the KPPU decision number 11/KPPU/L/2015. The study will use the normative legal research methods, analyze the constitution and analyze the case study. The result of the analysis shows that the victim violated Article 22 Constitution Number 5 of the Year 1999. Based on that Reported Party II, Reported Party III, and Reported Party IV has been charged with administrative sanctions, while Reported Party I, who is a tender committee only received a warning. Therefore, it is necessary to regulate the implementation of administrative sanctions to the tender committee to get a deterrent effect.