The clinical application of manometry of the lower esophageal sphincter (LES) remains controversial. This is because of the large variability in recorded lower esophageal sphincter pressure (LESP). In this paper a computerized method providing a three-dimensional image of the LES is described. In 12 healthy subjects end-expiratory rapid pull-through LESP recordings were performed for 1 h, using a perfused 8-channel probe. A cylindric model of the sphincter was calculated by means of a graphics program. The graphic representation of the LES demonstrated a circular pressure zone that was affected by the gastric migrating motility complex. This pressure zone was located proximal to a persistent indentation in the posterior and right posterolateral direction. Three-dimensional visualization of the LES provides additional information that cannot be obtained by the usually used techniques of analysis of sphincter manometry.