OVER THE past several years, autoimmunity has been identified as the cause of most common endocrine disorders. These disorders are clinically important diseases that affect many individuals. In addition, the pathogenesis of these diseases offers unique opportunities for investigations into immune regulation and autoimmunity. While rapid progress has been made in the identification of the autoantigens, autoantibodies, and cellular immune elements involved in the immune destruction or stimulation of endocrine glands, the specific mechanisms and susceptibility factors leading to the development of these diseases are not clear. Research into these unresolved questions will likely provide many insights into autoimmune disease and lead to prevention of endocrine system dysfunction. Proposed mechanisms for the development of autoimmune endocrine disease generally involve a multistep process. An initiating event likely entails nonspecific inflammation or trauma that results in a specific secondary immune response in a genetically susceptible individual. This specific immune response progressively destroys