Hydrogenation is one of the most important and widely used reactions in chemistry. It is indispensable for pharmaceutical, agrochemical and fine chemical industry, while numerous other applications are to be found in academia and industrial chemistry. Its significance is also reflected in the fact that the 2001 Noble Prize was awarded to Knowles and Noyori -- two pioneers in the field. This multi-volume handbook is the first to include all hydrogenation reactions catalyzed by soluble transition metal-based catalysts. As such, it presents in 25 clearly structured chapters the catalysts, the scope of their application, mechanistic aspects, asymmetric methods, combinatorials catalysis, recycling methods and industrial examples. The 36 authors adopt an applied approach, emphasizing those aspects important for industrial use. Following an historic introduction and a look at the mechanism of homogeneous hydrogenation, the book goes on to deal with kinetics, spectroscopic techniques and the homogeneous hydrogenation of alkenes, alkynes, dienes, aldehydes, ketones, esters and anhydrides. Further chapters are devoted to aromatic and heteroaromatic hydrogenation, dehalogenation reactions, homogeneous polymer, transfer and diastereoselective hydrogenations. Five chapters deal with asymmetric hydrogenations, and the whole is rounded off with a look at such techniques as high throughput experimentation and ligand libraries, two-phase aqueous hydrogenations, immobilization and catalyst deactivation. With some 2,000 illustrations and 50 tables, this is a must-have for everyone working in the chemicals and pharmaceutical industries, as well as for graduate students in chemistry.