The prognosis for patients with carcinoma of the esophagus remains poor despite the recent use of aggressive combination therapies and radical surgical resection. Attempts to improve the survival of patients with esophageal carcinoma have been confounded by a lack of effective therapeutic options in the later stages of the disease and an inability to accurately identify the early disease stages. Endoscopic ultrasound is a novel technique that affords close-proximity imaging of the esophageal wall and its adjacent structures. Endosonography is superior to CT scan for assessing depth of tumor penetration (T stage) and lymph node status (N stage). Recent advances in endoscopic ultrasonography include the ability to perform ultrasound-guided fine-needle aspiration of mediastinal masses and lymph nodes. Therefore, endosonography is ideally suited for staging esophageal cancers.