RESUMEN
S. Filippo Neri (1515-1595), founder of the Congregazione dell'Oratorio in Rome, was a longly debated clinic case for his various pathologies. Eminent scientists, like B. Eustachio and A. Cesalpino, treated him and drew up clinical reports, which were inserted in the Canonization Process and also published as scientific works, and which give useful informations about the history of medicine in the second half of the 16th century. Those reports relate, among others, about many diseases like frequent heart palpitation, shaking tremors heat flame and bronchitic fever episodes, that since hte age of thirty affected the saint. Autopsy revealed cardiac hypertrophia and pulmonary artery dilatation over twice the normal diameter. G. M. Lancisi was the first who formulated the hypothesis of an artery aneurysm, which, according to the present knowledge, can be produced by a post-stenotic dilatation of the pulmonary valve and/or pulmonary hypertension. Tremors and flames can be attributed to hyperthyroidism. Doctors who treated S. Filippo Neri and who shoved to be aware of his psychology, considered his pathology due to supernatural causes. Their conclusions can be understood basing on the medical way of thinking of that age, which was still linked to ancient medicine and limited by the biological and medical knowledge of the time.