This study aimed to investigate the effect of the internal parasites on the erythrocyte oxidative status through determining the activities of the antioxidant enzymes, catalaze (CAT), glutathione peroxidase (GSH-Px) and superoxide dismutase (DOS), in buffalo-calves. A total of 102 faecal samples were collected randomly from both sex buffalo-calves of one week — 12 months old, belonging to some private farms in Sharkia Province. The microscopic examination of faecal samples revealed that the prevalence rate of gastro-intestinal nematodes was 24.5% (Toxocara vitulorum 10.8%, Oesophagostomum radiatum 7.6% and Trichostrongylus spp. 5.9%). The infestation rate of trematodes (Paramphistomum) and Cestodes (Moniezia spp.) was 3.9% for both. Lastly, the percentage of Eimena spp. and Cryptosporiaum sp. was 4.9% and 2.9%, respectively in examined samples. The blood samples with anticoagulant were collected from only infested calves and used for determination of haemoglobin and evaluation of the level of malondialdehyde (MDA) and the activities of the antioxidant enzymes (CAT, GSH-Px and DOS) in the hemolysate. The results of this study revealed a significant increase in both the activities of the antioxidant enzymes and the level of MDA in the parasite infested calves than the healthy group, where the parasitic infestation as a stress factor led to release voluminous amounts of oxyradicals (free radicals and oxygen reactive species). So, large amounts of antioxidant enzymes are produced to neutralize these free radicals.