Autoimmune thyroid disease (ATD) is a multifactorial, genetic disease (ATD). Abnormalities in thyroid function and thyroid autoantibodies have been frequently described in patients with some rheumatological diseases as systemic lupus erythrematosus (SLE). Autoimmune route is one of the links between thyroid dysfunction and rheumatological diseases. The recurrent study included 20 patientswith rheumatological diseases, 20 subjects with thyroid diseases and 20 subjects as a control group who were undergone measuring the levels of ANA, Ads NA, Anti thyroid peroxidase (TPO) and Anti thyroglobulin (TG) for evaluation the relation between autoimmune thyroid diseases and connective tissue diseases.