Eimeria aurati n. sp. is described from the intestine of the goldfish, Carassius auratus, from Pennsylvania, U.S.A. Oocysts were very numerous in long, whitish, opaque fecal casts. They were 16 to 24 by 14 to 17 μ (mean, 20.1 by 16.3) and were non-sporulated when passed but sporulated 2 to 5 days later.