ABSTRACT Introduction: Thyroid disease is common in the general population. Hypothyroidism is often associated with elevated serum levels of total cholesterol, LDL-C and triglycerides. Thyroid hormone (TH) affects the production, clearance and transformation of cholesterol, but current research shows that thyroid-stimulating hormone (TSH) also participates in lipid metabolism independently of TH. Therefore, the mechanism of hypothyroidism-related dyslipidemia is associated with the decrease of TH and the increase of TSH levels. The current review focuses on the updated understanding of the mechanism of hypothyroidism-related dyslipidemia. Aim: To demonstrate the relationship between the hypothyroidism and dyslipidemia and antithyroid antibody. Patients and methods: This case control study was carried out on 162 adult subjects,54 patients with overt hypothyroidism and 54 patients with subclinical hypothyroidism attended the Endocrine out-patient clinic in Internal Medicine Department, Faculty of Medicine, Zagazig University Hospitals. The patients were divided into three groups Group (A): 54 subjects euthyroid (control), Group (B): 54 cases with SCH, and Group (C): 54 cases with Overt hypothyroidism Results: The results showed that TSH was significantly lower among control group with no significant difference between other two groups but regard FT3 and FT4 were significantly lower among Overt hypothyroidism Group with no significant difference between other two groups TG antibody significantly positive correlated with TAG in Overt group. TG antibody significantly positive correlated with TPO in Sub group. but No significant correlation in Control group. Conclusion: Thyroid dysfunction is one of the most common endocrine disorders and hypothyroidism might be associated with dyslipidemia by different mechanisms.Anti-thyroid antibody is an important index that reflects the prognosis of SH, and also aggravates vascular endothelial dysfunction leading to atherosclerosis. anti-thyroid antibodies may also affect blood lipid level, there by increasing the risk of cardiovascular disease