Sporulated oocysts (mean dimensions = 13.0 × 10.8 μm) and sporocysts (11.3 × 5.5 μm) of a coccidian resembling Frenkelia sp. or Sarcocystis sp. were present in the lamina propria of the small intestine of a naturally infected northern spotted owl (Strix occidentalis caurina) collected near Medford, Oregon (USA). Dimensions of these oocysts and sporocysts appear to be considerably smaller than those from other sarcocystid species with avian definitive hosts. Additionally, numerous developmental stages and unsporulated oocysts (mean dimensions 22.8 × 17.8 μm) of a possible species of Isospora also were observed in the intestinal epithelium. This constitutes the first report of enteric coccidia from spotted owls. Neither parasite appeared to cause the death of the bird.