The results of conventional capillary microscopy and fluorescence videomicroscopy are described in 7 patients with well established dermatomyositis (mean age 34.3 +/- 19 years, mean duration of the illness 25.7 +/- 26.9 months). All patients showed marked microangiopathy characterized by avascular fields, increased capillary tortuosity and enlargement, and enhanced transcapillary diffusion. The capillary microscopy pattern was not specific for dermatomyositis. Nevertheless, capillary microscopy plays an important role in the differential diagnosis of this condition. It remains unclear how sensitive this method is in the early detection of dermatomyositis.