The ancient Jewish law took a strict approach to medical relationships between Jews and non-Jews. The current study deals with the attitude of Amatus Lusitanus (1511–1568), a notable Portuguese Jewish physician towards treating gentiles. The Physician’s Oath of Lusitanus emphasises that as a doctor he treated people from varied faiths and socio-economic status. Lusitanus treated many non-Jews. For instance, he received an invitation from the municipality of Ragusa to serve as the town physician and he accepted this mission. In Anconare, he was called upon to treat Jacoba del Monte, sister of Pope Julius III, and he also prescribed for Julius himself. Amatus Lusitanus was forced to leave his country because of the Portuguese inquisition and wandered in many countries. Despite the hostile religious attitude of his close surroundings, he did not retaliate against his patients and provided medical treatment indiscriminately.