Background & Aims: Eosinophilic esophagitis (EoE) in adults, characterized by the triad of dysphagia, a ringed esophagus, and mucosal eosinophilic infiltration, has associated complications that include vertical mucosal lacerations, instrumental perforation, and emesis-induced rupture. The aim of this study was to determine whether clinical, endoscopic, and histologic features can be used to predict the risk for development of these complications. Methods: A review was conducted of 36 patients with EoE. Complications were defined as mucosal lacerations or radiographic evidence of perforation. Results: The mean age at presentation was 33.9 years. Twenty-eight (78%) patients were men. Complications occurred in 11 patients (31%). There were 7 mucosal lacerations, 3 perforations, and 1 emesis-induced rupture. Strictures were reported in 7 of 11 complicated cases compared with 2 of 25 of uncomplicated cases. Dilatation procedures had been performed in 6 of 7 complicated cases associated with stricture. Biopsy specimens obtained from 7 of 9 patients with complications showed 40 or more eosinophils/high-power field. There were no statistical differences between complicated and uncomplicated patients regarding demographics, clinical features, endoscopic characteristics, or histopathologic findings. Conclusions: EoE is a high-risk disorder with a range of complications. Although demographics, clinical presentation, and endoscopic features cannot distinguish risk, the presence of stricture, a longer duration of symptoms, and a greater density of eosinophilic infiltration suggest increased risk. The density of eosinophilic infiltration cannot be determined prospectively; therefore, the performance of endoscopy and subsequent dilatation should be deferred until biopsy specimens are reviewed or treatment is completed.