Summary Presented is the De Garvalho technique for the demonstration of a gastro-oesophageal reflux and discussed are its advantages in the demonstration of a “silent” hiatus hernia and/ or an unsuspected oesophagitis. Reviewed is the literature on the physiology of the lower oesophageal sphincter and on reflux oesophagitis. The results of the author are based on a review of 16,104 consecutive, unselected cases. From: The Department of Radiology, Queens Hospital Centre, Affiliation of the Long Island Jewish-Hillside Medical Centre, 82-68 164th Street, Jamaica, New York 11432, USA.