Standard endoscopy is an insensitive test for gastroesophageal reflux disease (GERD). Narrow band imaging (NBI) endoscopy enhances visualization of the distal esophagus. NBI patterns like intrapapillary capillary loop (IPCL) dilatation, tortuosity, and increased number; microerosions; increased vascularity at the squamocolumnar junction (SCJ); ridge-villous pattern below the SCJ; and presence of columnar islands in the distal esophagus have been suggested as features of GERD. We evaluated the effect of proton pump inhibitor (PPI) therapy on NBI findings in GERD patients. Patients prospectively underwent NBI upper endoscopy before and after PPI therapy. NBI findings were recorded at each endoscopy. Twenty-one patients with GERD symptoms (mean age 60.0 years; males 90.5%; white 90.5%) were studied. After PPI therapy, there was a significant reduction in the proportion of patients with the following NBI features: IPCL tortuosity (90% vs. 4.8%, P < 0.0001), dilated IPCLs (86% vs. 9.5%, P < 0.0001), and increased vascularity at the SCJ (43% vs. 9.5%, P= 0.0082). PPI led to healing of all microerosions (71% vs. 0%, P < 0.0001) and disappearance of ridge-villous patterns below the SCJ (14% vs. 0%, P < 0.0001). There was no significant change in the proportion of patients with increased numbers of IPCLs pre- and post-PPI therapy (71% vs. 48%, P= 0.09) or columnar islands in the distal esophagus (38% vs. 29%, P= 0.31). In patients with GERD symptoms, NBI features suggestive of GERD respond to PPI; suggesting these features are truly acid-mediated. These findings need to be confirmed by randomized controlled trials.