Barrett's esophagus is being diagnosed increasingly in the United States. The aim of this study was to determine whether the increased diagnosis of Barrett's esophagus is due to endoscopic reporting and/or a truly increasing rate. This retrospective study reviewed 18,183 endoscopy reports at Temple University Hospital from January 1991 through December 2000. Annual rates of new cases of endoscopically suspected Barrett's esophagus were determined. Biopsy results were reviewed for the diagnosis of Barrett's esophagus (i.e., specialized intestinal metaplasia). Rates of Barrett's esophagus increased from 3.22 to 8.28 per 100 endoscopies (257%; P < 0.01) on endoscopy and from 0.67 to 2.76 per 100 endoscopies (412%; P < 0.01) on histology from 1991 to 2000. Twenty-four and seven-tenths percent (252/1020) of patients suspected at endoscopy to have Barrett's esophagus were confirmed by histology. This study demonstrates an increasing rate of new cases of suspected Barrett's esophagus on endoscopy and confirmed Barrett's esophagus on histology over the last decade. The endoscopic impression of Barrett's esophagus was about four times higher than the confirmed diagnosis of Barrett's esophagus (intestinal metaplasia) on histology.