The study was conducted to determine the haemato-biochemical changes in calves with bottle jaw syndrome, which were brought for treatment at the Bangladesh Agricultural University Veterinary Clinic during the period from July to December 2002. A total of 15 calves with bottle jaw syndrome of either sex or aged between 6 to 12 months were selected for the study. Results on hematological examination showed significantly (p<0.01) decreased values of haemoglobin concentration, packed cell volume, total erythrocytes and total leucocytes count in calves with bottle jaw syndrome in comparison to normal healthy control calves. Biochemical values revealed significantly (p<0.01) decreased serum calcium, inorganic phosphorus, total serum protein albumin, and glucose levels in calves with bottle jaw syndrome. Serum iron decreased insignificantly and serum chloride value increased significantly (p<0.01) but the serum magnesium level increased insignificantly (p<0.05) in calves with bottle jaw syndrome in comparison to the healthy control calves.