This study examines the system of measures and weights used in Zenata trade in the Central Maghreb during the medieval period, by highlighting their economic functions and their role in regulating commercial transactions. The study reveals the diversity of standard units used in Zenata markets, which combined measures and weights based on Islamic legal standards with units commonly used throughout the Maghreb, in addition to local units associated with the Zenata region, such as al-Habsa, al-Kamsha, and Amsatran. The geographical expansion of the Zenata and the diversity of markets, together with the interaction of local customs, contributed to variations in the quantities represented by certain units from one region to another. The multiplicity of standards and the lack of precise regulation in some cases also led to the emergence of forms of fraud and short-weighing, through the manipulation of measures and weights and the use of various methods to reduce quantities and weights. The study highlights the role of the hisba institution, the political authorities, and jurists in monitoring measuring instruments, standardizing measurements, and confronting unlawful commercial practices, thereby contributing to the protection of traders’ rights and strengthening confidence in the markets. The study concludes that measures and weights were not merely technical instruments; rather, they constituted part of an economic, social, and legal system that reflected the relationship between standards, custom, and authority in Zenata society during the medieval period.