The present study is intended to detect internal parasites in faecal samples of local sheep in Kirkuk province, Iraq, through the period between March and the end of November 2022. where, 130 blood and faecal samples were collected and different laboratory investigations were carried out in the laboratory of the parasite, College of Veterinary Medicine, University of Kirkuk. The result indicated that 110 sheep (84.6%) were infested with gastrointestinal parasites. Most of the cases (64.3%) were mixed parasitic infestations, whereas (40.8%) were single parasitic infestations. at the following frequencies: (47.27%) Nematodes, (30.90%) Protozoa, (14.54%) Trematodes, and (7.27%) Cestodes. Haematological analysis results showed a significant decrease in red blood cell count, haemoglobin concentration, and hematocrit. Normocytic hypochromic anaemia was detected in the infected sheep. A significant increase in leukocyte counts is due to increases in lymphocytes, eosinophils, neutrophils, and monocytes. Results as well indicated a significant decrease in total protein, albumin, However, ALT, AST, and total bilirubin were elevated markedly. It has been concluded that GIT parasites have an adverse negative effect on animal health. Therefore, the rapid diagnosis and treatment of infected animals has become one of the priorities for maintaining the health of diseased animals.