EnThe present contribution focuses on the Neapolitan physician Giovanni della Penna, a scholar of the medical faculty of the studium of Naples in the fourteenth century. Giovanni was among the first physicians to publish regimina to ward off against or recover from the plague in 1348, and he got into a contentious debate with Gentile da Foligno. This analysis is meant to emphasize the originality of Giovanni's solutions, both when compared with his contemporary colleagues and with his classical and Arabic sources. Particular attention is paid to the recommended diet to prevent the disease or its complications, as well as to the use of precious stones as fundamental ingredients for anti-plague electuaries. Since he rejected Gentile da Folign...