The objective of this study was to investigate the oxidative stress parameter levels in navel inflammation (omphalitis) seen frequently during neonatal period. For this purpose, 10 clinically healthy calves as control and 20 calves with omphalitis at 1-2 months of age with different genders (16 males, 4 females) a total of 30 Brown Swiss calves were used. Blood samples were collected from V. jugularis for biochemical analyses. Some part of the blood samples were stored without any process as whole blood. The serum was seperated from remaining blood samples. Whole blood reduced glutathione (GSH), serum malondialdehyde (MDA) and nitric oxide (NO) levels were determined by colorimetric methods. Levels of MDA and NO were determined to increase in blood whereas GSH decreased in calves with omphalitis. In conclusion, the results indicated that omphalitis causes oxidative stress and lipid peroxidation.