The article is devoted to the analysis of the judicial system of the Fatimid Caliphate and the role of the caliph-imam in the organization of justice. The article examines the Mazalim institute as the highest judicial body, its functions in reviewing complaints, monitoring the activities of officials and settling interfaith disputes. The article examines the status of Qadi al-Qudat as the supreme judge, as well as the activities of the shurt and Muhtasib and the courts of zimmi responsible for law enforcement and law and order. The author draws a conclusion about the relative hierarchy of the judicial structure of the caliphate.