Left displacement of the abomasum (LDA) is one of the most important production disorders. In order to compare the status of some hematological and serum biochemical indices, trace elements and oxidative stress of cows with and without LDA, blood samples were taken from 30 dairy cows with LDA and 30 healthy cows in early lactation period. Haematological parameters, total protein, fibrinogen, Ca, Mg, bilirubin, uric acid, albumin, cholesterol, triglyceride, urea, creatinine and AST (Aspartate aminotransferase), ALP (Alkaline phosphatase), GGT (Gamma-glutamyl transferase), CPK (Creatine phosphokinase) enzymes, Fe, Zn, Cu, Se, MDA and total antioxidant status were measured. Although the results showed significant differences in PCV, RBC, MCHC, lymphocyte, monocyte, fibrinogen, bilirubin, albumin, cholesterol, calcium, uric acid, AST and ALP enzymes between the two groups (p<0. 05), but the occurrence of oxidative stress and changes in the levels of trace elements were not significant between the LDA affected and healthy cows. In LDA affected cattle, significant increase of PCV might be due to dehydration while increasing of monocyte and decreasing of lymphocyte counts could also be due to stressful condition or probable infections in early lactation. Anorexia, food deprivation and withdrawal of calcium from milk in early lactation may play a role in decreasing of albumin, cholesterol and calcium. Liver lipidosis and fasting along with biliary duct obstruction may be effective on increasing AST activity and bilirubin respectively in cows with LDA. It seems that early diagnosis and treatment of LDA can prevent the occurrence of sever changes in oxidative stress status and homeostasis of cow’ s body.