Identifying medicinal plant usage from the prehistoric record is problematic due to the preservation of such information, and the lack of conclusive evidence provided through dietary and non-dietary assemblages. One of the most direct methods of determining prehistoric medicinal plant usage is through the analysis of coprolites. This paper presents data gained through an analysis of 32 Archaic coprolites from. Caldwell Cave, Culberson County, in west Texas. The coprolites were analyzed for their pollen content in an attempt to identify flowers and/or inflorescences ingested purely for their medicinal value. High frequencies of Ephedra (Mormon tea) and Prosopis (mesquite) pollen were observed in the coprolites, and since these plants are known as diarrhetics, it is postulated that the Archaic peoples of Caldwell Cave probably used these plants as medicinal diarrhetics.