Barrett's esophagus (BE) is a metaplastic condition that occurs secondary to gastroesophageal reflux disease. BE is also a precursor to esophageal adenocarcinoma, which, although still rare in Japan, is one of the most rapidly increasing cancers in Western countries. However, the prevalence of gastroesophageal reflux disease has increased significantly over the past few decades in Japan, possibly ... [Show full abstract] leading to an incremental increase in BE and the associated inherent risk of adenocarcinoma. Given the poor prognosis of late-stage Barrett's adenocarcinoma, it is important to detect early neoplasias in patients with BE. However, endoscopic identification of early neoplasms is still not sufficiently reliable or subjective, making targeted biopsy by conventional endoscopy extremely difficult. During the last decade, newly-developed imaging technologies such as acetic acid enhancement and narrow band imaging combined with magnification endoscopy have enabled identification of early neoplasias. This article focuses on how to accurately detect and diagnose early neoplasias by conventional and advanced imaging technologies.