Coccidiosis caused by Eimeria spp. is a parasitic disease that affects various animal species, including sheep. This study aimed to detect Eimeria spp. and the degree of infection in the fat-tailed sheep breed in Malang. This study used fecal samples from 62 fat-tailed sheep. Detection of Eimeria spp. was performed by using the flotation method and then observed the morphology of the oocysts found in the fecal samples of fattailed sheep. The positive sample was followed by the McMaster test to calculate oocysts per gram (OPG). The results showed that 20 (32%) samples were positively infected by Eimeria spp. with the degree of infection in the severe category.