The chapter analyzes the nature and evolution of the administration of criminal justice in the Islamic Republic of Iran. Although current Iranian law incorporates a range of provisions intended to protect the rights of the accused in criminal prosecutions, in practice these provisions are routinely violated. It is argued that the violations of due process in the Islamic Republic of Iran are the result of several factors. First, the criminal justice system has been configured to deal with political opposition as an existential threat to the state, resulting in frequent executive interference in the judicial process and arbitrary trials in revolutionary courts. Second, the structural subordination of the judiciary to the effective power of the Supreme Leader and specific executive agencies has eroded the rule of law. Third, the ideological imperative to Islamize the judicial system after the 1979 Revolution has led to the adoption of judicial procedures that have given judges very wide discretion in the conduct and outcome of cases, notably in criminal law.