This paper will examine the commercial regulation of Egypt under the Fatimid caliphate from 969 to 1171 AD. Building upon Islamic doctrine, pre-existing Egyptian administrative policy, and a desire to promote local and interregional trade, the Fatimid caliphal bureaucracy developed a number of successful economic regulatory mechanisms that aided merchants of various class and creed in Egypt. Despite this relatively strong bureaucratic presence, the Fatimid administration avoided much of the corruption that plagued the administrative ranks of their successors, the Ayyubids and Mamluks. I argue that the Fatimid caliphs and their administrators were able to avoid significant levels of corruption and mismanagement due to their desire to project an image of piety. The legitimacy of the caliphate was based substantially on religiosity and therefore a projection of piety was essential to the government’s mandate. The muhtasib, charged with commanding the good and forbidding the wrong as well as with overseeing the marketplace, rose in prominence during the Fatimid era in connection with this emphasis on pious behavior. Many of the mechanisms used during the Fatimid era remained in use by Egyptian traders and administrators into the Ottoman era and beyond. Fatimid law created a flexible contract system which allowed for nearly any stipulation that did not defy Islamic legal norms. It also developed an open court system to which followers of various religious sects could appeal. Christian and Jewish merchants were sometimes explicitly protected by royal decree. In addition to pious concerns, administrative oversight by different departments in the Fatimid bureaucracy kept corruption, and therefore the cost of trading, relatively low. Lastly, Fatimid administrators minted high-quality coinage which was used throughout the Mediterranean region, creating an underlying system of trust in Egyptian currency, which also allowed for paper bills to be drawn and redeemed inside and outside of Egypt. These factors caused Cairo to emerge as a major commercial center in the Mediterranean during the Fatimid era.