The Constitutional Court of the Republic of Croatia, as an autonomous body sui generis, supervises the execution of imprisonment through abstract control of the constitutionality and legality of norms of Croatian penitentiary law and on the occasion of constitutional complaint for special protection of human rights and fundamental freedoms. The Constitutional Court of the Republic of Croatia has intervened with restraint through abstract review of the constitutionality of the Act on the Execution of Imprisonment Sentences. On several occasions, he ordered the executive power of the Republic of Croatia to make concrete commitments to improve the conditions of accommodation in Croatian penitentiary institutions. The Constitutional Court of the Republic of Croatia in the last fifteen years, under the influence of the European Court of Human Rights in Strasbourg, has significantly improved the legal standards for serving prison sentences and protecting the human rights and fundamental freedoms of prisoners. The graduate thesis presents an overview of selected, mostly recent practice of the Constitutional Court of the Republic of Croatia in the period from 2010 to the present, in the field of constitutional review of respect for prisoners' rights and analyzes legal standards established by reference to relevant practice of the European Court of Human Rights. Decisions of the Constitutional Court of the Republic of Croatia are presented on the basis of established violations of the constitutionally guaranteed rights of prisoners within the chapters on the right to humane treatment and protection of dignity, the right to health care and the right to an effective legal remedy.