When immune dysfunction affects two or more endocrine glands and other non-endocrine immune disorders are present, the polyglandular autoimmune (PGA) syndromes should be considered. The PGA syndromes are classified as two main types: PGA type I and PGA type II. We are reporting this case in which a patient had primary adrenal insufficiency, autoimmune hypothyroidism and insulin dependent diabetes mellitus and was diagnosed as ";;;Schmidt's syndrome";;; (PGA type II). This syndrome is a very rare autoimmune disorder and difficult to diagnose because the symptoms of this syndrome depends on the gland which gets involved first. Our patient was treated and improved with corticosteroid, thyroxine and insulin therapy.