Dermatomyositis is a rare inflammatory condition of the skin and muscles which is believed to be a paraneoplastic syndrome. The annual incidence of dermatomyositis is 0.7~1/100,000 in the general population, and the association of dermatomyositis and internal mali-gnancy has been reported to be 15~40%, in particular with bronchial cancer, breast cancer, ovarian cancer, and cancer of gastrointestinal tract. We experienced a case of ovarian cancer accompaning acute onset-dermatomyositis in a fourty eight-year-old premenopausal woman. Here we present the case with brief review of literatures.