Background: Dermatomyositis and polymyositis can be associated with an underlying malignancy. Objective: Our purpose was to describe a group of patients with dermatomyositis and polymyositis in whom ovarian carcinoma was diagnosed and to evaluate further the characteristics of the association between these diseases. Methods: A cross-sectional retrospective review identified 14 patients in a 45-year period (1950 to 1995) with dermatomyositis and polymyositis in whom an underlying ovarian malignancy was diagnosed. Clinical and laboratory data of these patients were reviewed, and immunofluorescent and hematoxylin-eosin–stained skin sections were examined. Results: The mean age at diagnosis of dermatomyositis and polymyositis was 59 years. Of the 14 patients, 11 had dermatomyositis, two had polymyositis, and one had an overlap disease. The 12 patients with dermatomyositis had distinctive cutaneous lesions. In eight, cutaneous biopsy specimens demonstrated variable histologic changes. Thirteen patients had signs of proximal muscle weakness, and myopathy was further demonstrated by electromyographic testing in 10. Creatine kinase levels were increased in 6 of the 10 patients tested. Dysphagia was present in five patients, but esophageal dysmotility was not demonstrated in three. Dermatomyositis and polymyositis preceded the ovarian malignancy in nine patients, were concomitant with it in four, and succeeded the ovarian disease in one. Conclusion: Physical examination and imaging techniques failed to detect early ovarian cancer in our patients with dermatomyositis and polymyositis. When detected (usually by abdominopelvic examination, in two by computed tomographic examination), it was advanced, and survival was poor. (J Am Acad Dermatol 1997;37:730-3.)