Brucellosis is a chronic zoonotic disease caused by brucella strains that adversely affects human and animal health. Increases or decreases in acute phase protein (APP) levels are observed in various infective diseases in cattle. In our study, it was aimed to investigate how the change in APP levels in cattle infected with Brucella abortus and which ones can be used as a marker. In the study, blood serum and plasma of 28 brucella and 10 healthy cattle collected from various cattle farm in Samsun were used. Rose bengal plate test and complement fixation test were applied to the serums. While serum amyloid A (SAA), haptoglobin (Hp), albumin, and total protein (TP) levels were determined in the blood serums taken from the groups, fibrinogen (Fb) level was determined in the plasma. As a result of the analysis, SAA 350.2 mg/L, Hp 1.57 g/L, Fb 14.58 µg/mL, TP 8.99 g/L, and albumin 2.99 g/L were found in the group infected with B. abortus. SAA 81 mg/L, Hp 0.41 g/L, Fb 2.1 µg/mL, TP 6.21 g/L, and albumin 3.57 g/L were found in the control group. Comparing the APP levels of cattle infected with B. abortus and the cattle in the control group, the levels of SAA (P < 0.05), Hp (P < 0.05), Fb (P < 0.05), and Tp (P < 0.05) were statistically significantly higher in the infected group, while the level of albumin (P < 0.05) was found to be statistically significantly decreased.