A patient with myotonia-dystrophica had an acute onset of severe and prolonged dysphagia. Cinefluorographic and intraluminal manometric studies of the esophagus demonstrated normal pharyngeal and cricopharyngeal function with severe motor failure of the body of the esophagus and gastroesophageal sphincter. These findings suggest that smooth as well as striated muscle can be affected by the dystrophic component of the disease.