Abstract: Italian physicians have been interested in geology since the fifteenth century or earlier, with leading figures carrying out fundamental and enlightening studies in both fields of competence. Refined cultured men including Bernardino Ramazzini, Antonio Vallisneri, Tommaso Antonio Catullo, Carlo Gemmellaro, Leopoldo Pilla, Giuseppe Meneghini, Gaetano Giorgio Gemmellaro and Arcangelo Scacchi, in addition to the introduction of reasoning and basic concepts for the advancement of Earth sciences, conducted major studies in the medical field, proving once again the holistic interests of Italian intellectuals. Following the publication of Principles of Geology by Charles Lyell, some scientists were fascinated by the geosciences, carrying out both medical observations and geological studies, and contributing significantly to the development of modern geology. The biographies and works of some leading Italian physicians illustrate their scientific activity in the study of stratigraphy, geomorphology, palaeontology and volcanology, with acknowledgement internationally. These Italian scientists contributed to the political unification of Italy, actively participating in scientific and political discussion, and fulfilling government aims. They contributed to the foundation of the Geological Society of Italy, one of the oldest scientific fellowships in Italy.