This book comprehensively introduces fundamentals and applications of fermentative hydrogen production from organic wastes, consisting of eight chapters, covering the microbiology, biochemistry and enzymology of hydrogen production, the enrichment of hydrogen-producing microorganisms, the pretreatment of various organic wastes for hydrogen production, the influence of different physicochemical factors on hydrogen production, the kinetic models and simulation of biological process of fermentative hydrogen production, the optimization of biological hydrogen production process and the fermentative hydrogen production from sewage sludge. The book summarizes the most recent advances that have been made in this field and discusses bottlenecks of further development. This book gives a holistic picture of this technology and details the knowledge through illustrative diagrams, flow charts, and comprehensive tables. It is intended for undergraduate and graduate students who are interested in bioenergy and wastes management, researchers exploring microbial fermentation process, and engineers working on system optimization or other bioenergy applications.