Barrett's esophagus is the most important risk factor in the development of adenocarcinoma of the esophagus. Barrett's esophagus is generally regarded as the most significant complication of gastroesophageal reflux disease. Adenocarcinoma occurs more frequently in the setting of high-grade dysplasia. The prognosis of adenocarcinoma of the esophagus is strongly correlated with the stage of disease. The prognosis of late stage disease is extremely poor. Cure may be achieved when disease is found at an early stage. Esophagectomy has been the definitive treatment of limited stage adenocarcinoma of the esophagus. The morbidity and mortality rate for esophagectomy is high. Therefore, alternative endoscopic methods for curative treatments have gained popularity. The two main endoscopic therapies, photodynamic therapy and endoscopic mucosal resection, are both effective when applied to early-stage disease. Traditional evaluation of the patient with Barrett's esophagus with high-grade dysplasia includes esophago-gastro-duodenoscopy (EGD) with biopsy and computed tomography of the chest. Endoscopic ultrasound (EUS) has gained popularity in the evaluation of the patient with Barrett's esophagus and high-grade dysplasia because it is the only imaging technique capable of delineating the separate histologic layers of the gastrointestinal tract. The principal role of EUS in evaluating patients with Barrett's-associated dysplasia is to identify patients who may be candidates for endoscopic ablative (endoscopic mucosal resection, photodynamic therapy) therapies. EUS has been shown to be superior to computed tomography (including high resolution spiral CT) or magnetic resonance imaging for preoperative staging in patients with high-grade dysplasia and carcinoma. This review of the literature summarizes the ability of EUS to evaluate patients with Barrett's esophagus and high-grade dysplasia.