The muscle-related complications of fasciitis and myositis, caused by chronic GVHD after Allo-SCT are relatively rare, but at times will severely impair a patient's quality of life (QOL). We performed a retrospective analysis in Japanese Allo-SCT recipients to identify the incidence, risk factors and clinical features of fasciitis and myositis. In 1967 patients who underwent Allo-SCT between January 1994 and March 2005 and survived beyond 90 days post transplantation, eight patients developed fasciitis and nine patients developed myositis, with a 5-year cumulative incidence of 0.55% and 0.54%, respectively. The median time from SCT to the development of fasciitis and myositis was 991 and 660 days, respectively. PBSCT was a risk factor for developing fasciitis, but no risk factors were found for myositis. The response to immunosuppressive treatment was better in patients with myositis than fasciitis, and the overall survival after developing these symptoms was better in patients with myositis than those with fasciitis. An early diagnosis by a biopsy, which includes fascia and muscle or magnetic resonance imaging (MRI) and prompt treatment may be important to prevent an impairment of the patient's QOL with persistent disability.