Along with concern for environmental quality and the anticipated return to an appropriate technology by highly developed nations, it behooves us not to ignore such natural forces — as the earthworm — that have made possible our existence as managers of the Earth. In order to plan for the future use (and exploitation) of earthworms, an understanding of their biology and capabilities is highly desirable. This review endeavors to delineate earthworm structure, functioning, and the effects of environmental factors on earthworm performance. The value of earthworms in agriculture, gardening, and soil improvement, in general, Is recognized. An attempt is then made to portray the benefits and limitations of earthworms as waste disposers, strip mine reclaimers, pollution indicators, and as a source of nutrients for animals or the human species.