Pernicious anemia appears to be autoimmune in origin and is associated with immune disorders of several organ systems. We report 4 patients with pernicious anemia and immune cytopenias, an association that may sometimes pose diagnostic problems unless specifically considered. Pernicious anemia coexisted with or was closely followed by idiopathic thrombocytopenic purpura in 3 patients and by autoimmune hemolytic anemia in a 4th patient. In addition to cobalamin therapy, all patients required corticosteroids (2 also received danazol), while 1 also required splenectomy. All 4 patients were women. The 3 patients with idiopathic thrombocytopenic purpura were also blood group 0 and were iron-deficient. Autoimmune cytopenias may occur in patients with treated or untreated pernicious anemia and require specific therapy.