||Twenty coprolites recovered from the excavation of Clyde's Cavern, Utah, were examined for dietary components, dietary change through time, and evidence of parasites. The samples are representative of possibly three prehistoric cultures of Utah; Late Archaic (ca. 1120 B.C.-ca. A.D. 1, Levels 1 and 2), possibly Basket-maker Anasazi (BM II ? ca. A.D. 1 - ca. A.D. 475, Level 3), and Fremont (ca. A.D. 400-A.D. 1200, Levels 4 through 8). The small sample size from the earliest occupation levels (Levels 2 and 3) does not permit a generalization about the diet of this period. However, during Fremont occupation the only change in diet is the addition of corn and Indian rice grass. Corn, until Level 8, appears not as a staple but as a component of a composite diet of various seed types and non-seed plant material. Thus, the concept that the Fremont is but a horticultural accretion to Desert Archaic roots is not refuted (see Marwitt 1971). Throughout the human occupation of the cave the diet appears to reflect a pattern characteristic of the Desert Archaic lifeway. At least nine varieties of seeds were utilized together with non-seed plant material and small amounts of animal protein. The evidence of grit in all coprolites, and charcoal in most, suggests that some foods were roasted and milled before being ingested. Prehistoric man at Clyde's Cavern was heavily parasitized by the human pinworm. He may also have been parasitized by species of Strongyloides, and Acanthocephala. The methods of analysis were essentially those utilized by Fry (1970), however, certain modifications were made which added rigor and efficiency to the analysis.