Abstract: The present study aimed to investigate oxidant/antioxidants status and some biophysical properties of hemoglobin in preweaning buffalo calves in relation to their vitality. A total number of 253 buffalo calves (2-3 months old) were clinically examined, the vitality of these animals were recorded and blood samples were collected for determination of some oxidant-antioxidant values, as well as some hemoglobin biophysical properties. Results indicated that 38.74% of the examined calves showed preweaning inferior vitality as indicated by dullness, low growth rate, rough coat and signs of scoring. Inferior vitality calves have high malondialdehyde (MDA, p<0.001) and nitric oxide (NO, p<0.001) and low catalase (CAT, p<0.001), superoxide dismutase (SOD, p<0.001), ascorbic acid (p<0.01), glutathione reduced (GSH, p<0.001), total antioxidant capacity (TAC, p<0.001), zinc (Zn, p<0.01), copper (Cu, p<0.01), iron (Fe, p<0.05) and selenium (Se, p<0.001) in their blood. The electrical conductivity and derivatives of hemoglobin non significantly changed due to calf vitality. In conclusion, there is a tight relationship between oxidant/antioxidant status of buffalo-calves and their preweaning vitality.