Sarcocysts were found by light microscopic examination of muscle in 199 (51%) of 390 white-tailed deer (Odocoileus virginianus) from the southeastern United States. Sarcocystis infections were detected more frequently in histologic sections of tongue (45%) than of heart (9%). Sarcocysts were significantly more prevalent in adult deer (54%) than fawns (26%) (P<.01). Statistically significant differences in prevalence were not found in deer from different physiographic provinces or between sexes. Artificial digestion was more sensitive in detecting Sarcocystis infections than examination of histologic sections when both techniques were used to examine tongues of 35 deer. Three different size sporocysts, possibly representing at least two species of Sarcocystis, were recovered during feeding trials. Seven dogs (Canis familiaris) shed sporocysts 9 to 12 days after eating infected venison. Sporocysts measured 13.4–16.8 × 9.0–12.3 μm with an average measurement of 15.2 × 10.9μm (N=195). One of three cats (Felis catus) and one of two red foxes (Vulpes vulpes) first shed sporocysts of Sarcocystis 10 days after eating infected venison. Sporocysts from the cat measured 11.2–13.4 × 6.72–8.96μm (avg 12.0 × 8.7μm, N= 18), and those from the fox measured 11.2–15.7 × 9.0–11.2μm (avg 13.6 × 10.2μm, N=7).