This study was conducted to determine the change in the positive acute phase proteins in sheep with acute ruminal lactic acidosis. The study was performed on 20 sheep consisting of 10 sheep with ruminal acidosis and 10 healthy controls. Blood samples were taken from the jugular vein of the animals and analyzed as soon as possible. The levels of acute phase proteins such as serum amyloid A (SAA), haptoglobulin (Hp) and C-reactive protein (CRP) were determined by ELISA using appropriate commercial test kits. Although the significant differences (P<0.01) were determined in SAA and Hp levels between acute lactic acidosis group and healthy control, the significant changes (P<0.05) wasn’t determined in the CRP level. In conclusion, it is thought that the findings obtained from this study will be a resource for similar studies and that it will be beneficial to follow up the treatment and perform new studies at the prognostic point.