The contents of this book has been the subject of a lecture course, which the first author has held regularly for engineering students at the Technical University of Karlsruhe beginning in 1987. The book serves two purposes. It introduces students in their fourth year study of basic engineering and grad­ uate students to the fundamentals of magnetohydrodynamics. Furthermore, it may be used by engineers and physicists in research establishments and industry as a practical tool to become familiar with the particular phenom­ ena of magneto-thermohydraulics that they may encounter in technical liquid metal flows under the influence of magnetic fields. The contents and structure of the book are motivated by the research and development work for a self-cooled liquid metal blanket of future nuclear fu­ sion reactors. The research requirements for such a challenging project natu­ rally lead to the frontiers of magnetohydrodynamic research. This is reflected in the book by references to several publications and reports performed at the Forschungszentrum Karlsruhe and other research establishments. However, we are convinced that the advancement of magnetohydrodynamic knowledge gained within the framework of the Fusion Reactor Project may be utilized in other fields of engineering sciences.