Musculature containing grossly visible cysts of Sarcocystis rileyi from northern shoveler (Anas clypeata) ducks was fed to the striped skunk (Mephitis mephitis). Skunks used were determined to be Sarcocystis free, the challenged skunk became infected and shed both sporulated oocysts and free sporocysts in the feces. The prepatent period was 15 days and the patent period 50 days. Oocysts were fully sporulated when shed and contained two sporocysts, free sporocysts averaged 9 × 13.5 μm (N=50). Each sporocyst contained four sporozoites and a granular residuum.