This paper discusses the emergence of new medical experimental specialties at the Medical School of Surgery ( Escola Médico-Cirúrgica ) and the Faculty of Medicine of Lisbon University ( Faculdade de Medicina da Universidade de Lisboa ) between 1897 and 1946, as a result of the activities of Marck Athias's (1875-1946) histophysiology research school. In 1897, Marck Athias, a Portuguese physician who had graduated from the Faculty of Medicine in Paris, founded a research school in Lisbon along the lines of Michael Foster's physiology research school in England and Franz Hofmeister's physiological chemistry school in Germany. His research programme was highly innovative in Portugal. Not only did it bring together many disciples and co-workers, but it branched out and created new medical specialties within Portuguese medical science. These new disciplinary areas grew out of the study of the histology of the nervous system but eventually expanded into normal and pathological histophysiology, physiological chemistry and experimental endocrinology. The esprit de corps that existed between research school members ensured the school's success and influence in various fields social and political as well as scientific. Athias's school was strongly influenced by positivist ideals and promoted a teaching and research style that sought inspiration in Humboldt's university model, thus helping to bring about a change in the dominant scientific ethos and to modernize scientific research in Portugal during the first half of the twentieth century.