The subject of this diploma paper is illegal evidence. The quality of the investigation in the criminal proceedings, and then the judgment as final outcomes of criminal proceedings based on facts - evidence. Illegal evidence is the evidence that due process violations of form which also constitutes a breach of fundamental human rights should not be used to render a judgment in criminal proceedings. The decision on the basis of which the evidence to be adjudicated, always based on the basis of determining two interests. On the one hand there is the protection of human rights and the rights of defense of the state bodies and citizens must be followed when collecting evidence and which have international legal and constitutional rank on the other hand the state is obliged to effective prosecution and the prevention of crime and punishment of the perpetrators.It is important to stress that The Criminal Procedure Code provides that the court judgment can not be based on illegally obtained evidence. In the case of the finding that it is unlawful evidence, the competent authority shall establish that the protection of fundamental rights of the individual outweigh the obligation of the state to use this evidence for the prosecution in order to its effectiveness. The right to human dignity as the highest common good, should not be subjected to any weighing of interests, including weighing from the standpoint of criminal procedural law is extremely important for the interests of the efficiency of criminal prosecution and interests protection defendant rights and freedoms.In preparing this work was used appropriate scientific literature in the field of criminal procedural law on evidence and specialized magazines in the field of law and Internet sites.