Esophageal motility studies, which are simple and harmless to the patient, should form a definite part of the investigative pattern of all lesions of the esophagus. The method to be used has been discussed. Deviations from normal patterns in hiatal hernias, achalasia, vestibular spasms, diffuse spasm, thoracic pain differentiation, postvagotomy syndrome, scleroderma, and benign and malignant tumors have been enumerated. These deviations from the normal assist the physician in making the specific diagnosis, indicate in many cases the form of treatment to be adopted, and finally, as a preoperative modality, especially in hiatal hernia, make certain procedures mandatory in order to obtain excellent results.