Dermatomyositis (DM) is characterized by concurrence of proximal muscle weakness and inflammatory skin lesion with a specific anatomical distribution, although the hypomyopathic type also occurs. Aside from muscular and dermatologic abnormalities, dermatomyositis is known to be associated with internal malignancy in about 10% to 40%. A 54 year-old woman presented with erythematous papules and plaques symmetrically distributed on the face and trunk, which started a month ago. Reddish papules with itchiness on the knuckles, namely Gottron’s papules, were also observed. In addition, muscle weakness was prominent regarding the shoulder and pelvic girdles. Skin biopsy performed on the upper back and its result was consistent with DM. Serologic exam showed elevated levels of aldolase and creatine kinase. Diagnosis of dermatomyositis was established by the characteristic skin lesion, involved muscle distribution, muscle enzyme study, and histopathologic finding of the skin. The patient received corticosteroid therapy and further studies identified ovarian cancer based on computed tomograpgy scan and elevated tumor marker such as CA-125. We authors suggest that Dermatologists should always be aware of the posibility of malignancy, especially gynecologic tumors when confronting patients with DM. Herein, we report a clinically important case of dermatomyositis associated with ovarian cancer.