Structural or functional abnormalities of the distal esophagus were demonstrated by cineradiography in 14 of 16 patients with polymyositis or dermatomyositis who had been incompletely responsive to high dose corticosteroids and, in some cases, immunosuppressive therapy, or who had adverse effects associated with these therapies. These distal abnormalities occurred in the absence of proximal esophageal skeletal muscle dysfunction in 70% of patients, usually were more frequent with increasing disease duration, and were functionally similar to abnormalities reported in scleroderma. Symptomatic improvement occurred to some patients with administration of antacids and measures designed to decrease esophageal reflux, but improved esophageal symptoms did not correlate with improvement in the myositis. In 18 autopsy subjects with similar histories, distal esophageal smooth muscle atrophy and fibrosis occurred in only 1 and 2 cases, respectively. Of 5 in whom distal esophageal dysmotility had been documented ante-mortem, only 1 had fibrosis and none had smooth muscle atrophy. These findings suggest that factors other than fibrosis and muscle atrophy may contribute to distal esophageal dysmotility in polymyositis and dermatomyositis.