This article takes a look at the guardian role of saints in Christian tradition against particular diseases, focusing on the life of St Francis of Assisi and his 13 follower saints who were remembered for their care for the ill and who became patron saints for particular diseases, including Anthony of Padua, Clare of Assisi, Ottone of Pola, Elizabeth of Hungary, Rose of Viterbo, Bernardine of Siena, Didacus, Mark of Montegallo, Joseph of Leonessa, John Joseph of the Cross, Giles Mary of Saint Joseph, Francis Mary of Camporosso, and Leopold Mandić. For each of them the article presents a brief hagiography and explains the relationship with a specific disease and how these saints became patrons.