Urbanization is a term that represents the level of urbanization relative to the overall population living within urban areas. The rate of urbanization, on the other hand, refers to the speed at which a country is urbanizing. Urban areas have long been associated with economic growth and prosperity. However, as populations, industries and services get attracted to urban centers, urbanization, if not well managed, may come with a number of environmental challenges, prominent among which are water and air pollution, poor solid and liquid waste management, disappearance of urban greenery, loss of biological diversity, and sub-urban sprawl. The environmental challenges faced by urban planners and managers, as well as urban dwellers in general form the basis of this book. The book tries to highlight the causes and effects of these environmental challenges, particularly in less developed countries, and suggests possible codes of practice that might minimize the challenges. Among the suggestions proffered is the need for environmental education, public involvement and urban planning that integrates environmental considerations at all stages of urbanization and urban development.