Sexual abuse of children is a major problem in society, and state, as well as its citizens, must do everything to stop it. The aim of this diploma paper is to point out how is criminal law involved in solving the problem of sexual abuse of children. The material and procedural legal provisions determine which criminal offenses are committed to the detriment of the child and how to make the entire procedure as less painful to the child and how to protect and help the children. Identification of abuse and appropriate treatment of victims is also preventative action, and apart from the legislators themselves, different institutions are also involved on the basis of the law. At the very beginning of this diploma paper we will explain what is sexual abuse of children and how it was treated in the past. We will categorize the perpetrators of the mentioned criminal offense and specify which criminal offenses are prescribed by the Criminal Code and which are the characteristics of such sexual crimes. Since the victims of this criminal offense are children, we will point out the particularities of criminal proceedings and the treatment of children as witnesses. Then we will say something about the victim's support, what kind of prevention exists, and at the end of this diploma paper we will explain which international standards are to be complied with by our legislation.