Latent autoimmune diabetes in adults (LADA) is characterized by clinical presentation as type 2 diabetes after 25 years of age, initial control achieved with diet or oral hypoglycaemic agents during at least 6 months, presence of autoantibodies (first of all GADA) and some immunogenetic features of diabetes mellitus type 1. In patients with an autoimmune endocrine disease, which could be also autoimmune diabetes, there is a high risk of development of another autoimmune endocrine disorder. The coexistence of two or more autoimmune endocrine diseases is pathognomonic for autoimmune polyglandular syndrome. Autoimmune thyroiditis and type 1 diabetes mellitus are the most common combination of autoimmune endocrine diseases reported. Most studies reported the prevalence of autoimmune thyroiditis in "typical" type 1 adult diabetic subjects about 20 - 40%. Little is known about the prevalence of autoimmune thyroiditis in subjects with LADA. Only a few studies confirmed a high prevalence of thyroid autoantibodies in type 2 diabetic subjects with GADA compared to type 2 diabetic subjects without GADA and compared to non-diabetic population too.