Medieval business ethics is a topic of recent interest among historians. This study examines a case of commercial fraud, the falsification of saffron, in the southern French town of Montpellier in the mid-fourteenth century. Impure saffron was seized by urban inspectors at the workshop of a pepperer, Johannes Andree. Upon the testimony of witnesses, the impurity of the saffron was corroborated, and municipal justice decreed that it be publicly burned. Johannes Andree chose to contest this verdict, claiming exemption from judgment upon the grounds that he was a royal moneyer. A conflict of jurisdiction ensued, with the vector of Montpelliéret supporting Andree against the municipal consuls and the town bailiff. This study focuses on the documentary evidence of the law suit: the nature of the accusation against Andree, the legitimacy of his defence, the precedents for consular supervision of the pepperers' trade and the importance of quality control over merchandise, and the background of the jurisdictional dispute between the consuls and the rector. Finally, the legal terminology of this case of commercial fraud is considered in the context of legal theory and medieval jurisprudence. From this analysis of municipal justice in practice, standards of business ethics, consumer protection and quality control emerge as important concerns in a trading centre such as Montpellier.