There are many studies exploring the topic of acute phase response and oxidative status in inflammation of the mammary gland of cows. However, many phenomena are relatively not well known. Mastitis is associated with significantly higher concentrations of inflammatory and oxidative mediators in the cells and blood. Results of experiments have shown that there are evident changes in serum interleukins (IL), acidglycoprotein (alpha1AG), tumor necrosis factor (TNF), and haptoglobin (Hp). Thus, local as well as systemic inflammation might play important roles in increased mammary oxidative stress. Reactive oxygen species (ROS) have been implicated in the pathogenesis of a variety of diseases, including mastitis and in transgenic technology leading to production of new bacterial proteins, very important in prevention of mastitis. We can also observe an interaction between inflammatory and oxidative mediators. These results suggest an important role played by acute phase response and oxidative status in inflammation of the mammary gland.