Autoimmune thyroid disorders (AITDs) are the most common organ-specific autoimmune disorders. The genetics as well as clinical and laboratory manifestations of AITDs are reviewed.We discuss the association between specific rheumatologic disorders and AITDs and manifestations of AITDs that mimic rheumatologic disorders. The recently discovered common molecular pathways involved in these processes are discussed.AITDs and rheumatologic disorders have significant commonalities both clinically and etiologically. This information is important for rheumatologists and primary care physicians who care for patients with these disorders.