Bioremediation is an expanding area of environmental biotechnology, and may be defined as the application of biological processes to the treatment of pollution. Much bioremediation work has concentrated on organic pollutants, although the range of substances that can be transformed or detoxified by micro-organisms includes both natural and synthetic organic materials and inorganic pollutants, such as toxic metals. The majority of applications developed to date involve bacteria and there is a distinct lack of appreciation of the potential roles and involvement of fungi in bioremediation, despite clear evidence of their metabolic and morphological versatility. This book highlights the potential of filamentous fungi, including mycorrhizas, in bioremediation and discusses the physiology and chemistry of pollutant transformations.