The book describes the collection of the Museum Engines and Mechanisms of the University of Palermo, Italy, one of the most important and heterogeneous collections of engines and mechanisms in Europe, the first one in Italy to be awarded as Mechanical Engineering Heritage Collection by the American Society of Mechanical Engineers. Thanks to its numerous items, this book showcases the evolution of fluid machinery and applied mechanics, from steam engines up to turbojet engines, as well as hybrid system, giving several technical and historical information about its most important engines, which are described in detail through pictures and original drawings. The Museum preserves and makes freely available this almost unique collection of more than 300 engines, didactic models, and technical equipment, including various unique exemplars, continuously enhanced thanks to donations and through restoration activities carried out in a dedicated laboratory of the Museum. As a result of a great deal of philological research carried out on the documents collected in the Museum's archive, as well as in other institutional and corporate historical archives, this book serves as the reference tool of the collection and, more generally, of the Museum itself. Despite the technical subject and the academic environment in which it was created, the catalogue is realized to be read even by non-experts, offering different levels of detail, the first of which is the historical, economic and, in certain cases, even sporting context related to an engine, such as the vehicle for which it was designed and used.