We report a patient with combined polycystic ovary syndrome (PCOS) and autoimmune polyglandular syndrome (APS) type 2. A 26-year-old female presented with polyuria, polydipsia and acute weight loss. She was diagnosed with: (1) type 1 diabetes, with hyperglycemia, impaired insulin secretion, and positive autoantibodies for GAD-65 and IA-2; (2) autoimmune thyroiditis, with hypothyroidism, positive anti-microsomal and antithyroglobulin antibodies; and (3) PCOS, with hyperandrogenic signs that had developed 5 years earlier, amenorrhea for the previous 6 months, and characteristic multiple microcystic appearance of both ovaries on ultrasonography. She is being treated with multiple subcutaneous insulin injections, thyroxine replacement, and cyclic medroxyprogesterone for the aforementioned diseases, respectively. Although several investigations have reported a relationship between PCOS and the individual components of APS, this is the first report of both syndromes occurring simultaneously. Potential mechanisms for their interrelation and the possibility that PCOS is an autoimmune disease are discussed.