Barrett's esophagus, or columnar metaplasia with gastric cardiac cells or intestinal cells, develops in the squamous epithelium of the esophageal mucosa in relation to gastroesophageal reflux. An increased risk of neoplasia justifies surveillance at regular intervals. Conventional guidelines recommend detection of areas with intestinal metaplasia or dysplasia by taking random four-quadrant biopsies at every 1 or 2 cm. Alternatively, image processing with narrow band imaging (NBI), is proposed to improve detection. This international and randomized study in persons with Barrett's esophagus compares conventional endoscopy in white light with random four-quadrant biopsies and NBI imaging with focused biopsies only. Randomization enrolled 123 patients with Barrett's esophagus who successively underwent exploration with the two methods. The study confirmed that NBI had the same efficacy as white light in the detection of intestinal metaplasia, with a higher proportion of dysplasia detected (30 vs 21%) and a lower number of biopsies per patient (3.6 vs 7.6).