We report the results of nine patients with inclusion body myositis treated with intravenous immunoglobulin in an open-label uncontrolled study. None of our patients improved on objective manual muscle testing or functional disability scores. One patient developed mild neutropenia, complicating the intravenous immunoglobulin treatment. Our results do not exclude the possibility that intravenous immunoglobulin could be beneficial in some patients by slowing the rate of deterioration or perhaps stabilizing the disease. However, given the lack of objective improvement and high cost of treatment, we would not recommend intravenous immunoglobulin in the treatment of inclusion body myositis unless a blinded, controlled trial demonstrates clear benefit.