This report describes the case of a 47-year old man who developed myositis in association with hepatitis B surface antigen-positive hepatitis. Interestingly, the myositis repeatedly worsened 2 months after the exacerbation of hepatitis in this case, suggesting a close association between hepatitis B infection and myositis. The dose of prednisolone was increased twice in order to treat the exacerbating myositis, resulting in improvement of the muscle symptoms, but the patient eventually died of liver failure. Only 5 other myositis patients with hepatitis B antigenemia have been reported in the literature. We review these cases of the association between hepatitis B infection and myositis.