The increased interest in studying the uses of soil for purposes other than food and ber production came at a time of immense interest in understanding the conscious ingestion of clay by humans, a practice referred to as geophagy. Many cultures ingest soils as part of their traditional medicine, for dietary supplements, and as a general pastime (Henry and Cring, Chapter 8, this volume; Abrahams, 2005; Abrahams and Parsons, 1996; Vermeer, 1985; Hunter and de Kleine, 1984). The objectives of this chapter are to (a) describe the origin, nature, and composition of soil clay minerals in relation to human health; (b) discuss the chemical and mineralogical properties of soils that make them suitable for nutritional, medicinal, and other uses; (c) identify medicines from soils; and (d) discuss soil-related human health issues and diseases.