Autoimmune thrombocytopenic purpura (AITP) is an autoimmune disorder that results from antiplatelet autoantibodies; these autoantibodies cause platelet destruction in the reticluoendothelial system. Oral corticosteroid therapy is the first line treatment. Splenectomy is the major treatment modality after the failure of more conservative medical therapy. Approximately 15% of the patients will relapse either soon after splenectomy or, as is less common, many years later. The presence of an accessory spleen should be sought. We experienced a patient with a known diagnosis of autoimmune thrombocytopenic purpura who had a worsening thrombocytopenia 11 years after splenectomy. This patient was diagnosed with an accessory spleen. Accessory splenectomy was performed with only a transient elevation of the platelets. We report here on this case with a review of the literature.