Graft-versus-host disease (GVHD) remains a major complication of allogeneic hematopoietic stem cell transplantation. Polymyositis can occur in association with chronic GVHD and mimics the idiopathic form of the disease. We report two cases of chronic GVHD-associated polymyositis and review the published literature. The two patients presented 13 and 19 months after allogeneic transplantation with characteristic features of muscular hypotrophy, proximal muscle weakness, pain, elevated creatine phosphokinase (CPK), aldolase and SGPT. Interestingly, both patients had HLA DR52 genes, which is frequently reported in association with idiopathic polymyositis. Electromyogram (EMG) and muscle biopsy confirmed the diagnosis. Treatment with cyclosporine or tacrolimus resulted in complete and sustained remission of polymyositis in both cases. A review of the literature shows cyclosporine and steroids are well-described treatment options for patients with myositis in post transplant, as well as idiopathic cases. The duration of immunosuppressive treatment has varied in different reports, and there is a risk of recurrence when immunosuppression is tapered.