1. The roentgenographic and physiologic features of the normal swallowing complex have been reviewed and are related to roentgen manifestations of motor dysfunction, notably diffuse esophageal spasm. 2. A roentgen technique for demonstrating diffuse esophageal spasm is described. a. The important point in this technique is that sufficient barium must be given to ensure maximal esophageal distention, which is a requisite for the stimulation of the abnormal contractions. b. The cardinal observation to be made fluoroscopically is the absence of penistalsis in these patients. 3. The view has been expressed that diffuse spasm should be diagnosed by proper roentgen techniques alone. Complicated motility measurements are considered unnecessary.