The article concerns the problem of compulsory treatment of perpetrators of crimes committed in connection with disorders of sexual preferences. Amendments to the Penal Code of November 5, 2009, introduces a new, previously unknown to Polish criminal law precautionary measure, popularly called „chemical castration” (Article 95a of the Criminal Code). This issue became the subject of much discussion of society. In addition to general characteristics of the new penal measure in question will also be discussed the merits of this solution from the perspective of the protection of constitutional rights and freedoms.