In a retrospective study, the files of 19 patients with dermatomyositis examined at our departments from 1970 to 1993 were reviewed. The parameters studied were age, sex, muscle enzyme values, muscle biopsies, electromyographical findings and interval from onset of dermatomyositis until first visit to the department. Out of 19 patients with dermatomyositis, 18 were adults and in nine of these the condition was associated with cancer (three out of three men, six out of 15 women). Electromyographical findings were pathological in 17 investigated patients and myositis was indicated in 13 out of 15 biopsies. Muscle enzyme values were elevated in seven out of nine patients with cancer and in three out of nine without. Out of five patients with dysphagia, four patients had cancer. The risk of cancer is increased in patients with dermatomyositis. Factors indicating a poor prognosis regarding the association between dermatomyositis and cancer in our study were old age, male sex and dysphagia.