The aim of this study is to determine C. parvum in small intestinal samples of lambs (up to 30 days old) with enteritis. For this aim, fresh intestinal smears prepared from 60 lambs (euthanized due to diarrhea) and stained with Modified ZiehlNeelsen (MZN). In addition to these 60 fresh samples, 85 different small intestinal samples obtained from dead lambs (total 145 small intestinal samples) were embedded in paraffin for histopathology, immunofluorescence (IF) and immunohistochemistry (IHC). Slides were stained according to protocols (MZN, hematoxylin-eosin, IHC and IF). In MZN staining, 13.3% of smear samples were found positive for Cryptosporidium spp. Besides, C. parvum positivity was detected in the rate of 13.8% in IF and IHC stains. In the histopathologic examination, desquamation and necrosis of intestinal epithelium, villus atrophy, Cryptosporidium spp. along the surface of villus epithelium, hyperemia, mononuclear cellular infiltration, mitosis in crypt epithelium, intraepithelial lymphocytes, dilatation in the lymphatic canal and Eimeria spp. in some cases were observed in varying degree. In conclusion, IF, IHC and MZN stains were found effective in revealing cryptosporidiosis in lambs.