The book, titled “Thermo-Haemo-Dynamics in Medical Engineering”, presents some of the researches carried on by Fabio Gori Ammannati and his coworkers during 50 years of Academic career in several Italian and foreign Universities, teaching Thermodynamics, Fluid Dynamics, Heat and Mass Transfer. The researches presented in this book are relative to the application of the basic theoretical principles of Thermodynamics, Fluid Dynamics, Heat and Mass Transfer to the solution of medical problems in the human body. The topics presented are relative to Cryosurgery; Microwave heating and medical hyperthermia; Human body thermoregulation; Thermo-Haemo-Dynamics (THD) in coronary stents; Design of a hydraulic circuit for the study of vascular problems; Thermo-Haemo-Dynamics (THD) and Magneto-Hydro-Dynamics (MHD); and Cardiac Acoustics. The term Thermo-Haemo-Dynamics is employed in order to be distinct from the more common Fluid-Dynamics for the following reasons. The general Fluid Dynamics approach is relative to the solution of the four scalar equations, known as Navier-Stokes, which include the mass conservation (one scalar equation) and the momentum conservations (one vectorial equations or three scalar equations) of a fluid which is considered generally to behave according to Newton’s law. Thermo-Haemo-Dynamics, THD, besides the use of the four equations of Navier-Stokes, intends to solve at least one of the followings: the scalar equation of conservation of energy (derived from the First Principle of Thermodynamics); the scalar equation of entropy conservation (derived from the Second Principle of Thermodynamics); the scalar equation of mass diffusion of a chemical component and the equations of other associated physical phenomena, as, for example, sound wave.