We describe 17 full-term newborns presenting with vague symptoms related to the upper gastrointestinal tract (anorexia, poor feeding, retching, regurgitation, and incessant crying) during their stay in the maternity unit. After an esophagogastroduodenoscopy performed between days 2 and 5 of life, the babies could clearly be divided into two groups. Twelve babies (group 1) had an extremely severe esophagitis (circular ulcerations), without gastroduodenitis. In the remaining five babies (group 2), the upper gastrointestinal tract was unaffected. Allergic, infectious, metabolic, and toxic etiologies were excluded. Esophageal pH monitoring data were within normal ranges in all. All babies of group 1 were treated as follows: prone anti-Trendelenburg position, cisapride, and cimetidine syrup. Symptoms and lesions disappeared within 48-72 h. Reendoscopy after 72 h showed an almost normal esophagus with greatly improved histology. These observations highlight four points of interest: (a) the existence of an extremely severe ulcerative esophagitis in apparently healthy newborns, (b) the very rapid clinical and histological recovery, (c) the difficulties in predicting esophagitis on clinical grounds, and (d) the mysterious origin despite thorough assessment. The distribution of the lesions (more severe in the upper esophagus), the early onset (almost at birth), the very rapid healing, and the absence of gastric and duodenal lesions are in favor of a possible "traumatic" origin (pharyngeal, esophageal, and gastric suction at birth). Finally, because the condition described is transient, questions arise regarding the necessity of treatment, and we currently do not recommend overtreating newborns presenting with similar symptoms and/or endoscopic findings.