Over the past decades, the epidemiology of gastric cancer, Barrett’s esophagus and esophageal adenocarcinoma have shifted dramatically, with some populations in the west reporting several folds increase in the incidence of Barrett’s esophagus and esophageal adenocarcinoma. In Asia, rising incidence in esophageal adenocarcinoma has been reported in Singapore. Although the overall incidence of gastric cancer has decreased in many regions, gastric cancer remains one of the top killers worldwide, and is particularly prevalent in developing countries. The incidences of gastric cancer, Barrett’s esophagus and esophageal adenocarcinoma vary widely from region to region, and are dependent on genetic, economic and socio-environmental factors. Among them, dietary factors and Helicobacter pylori infection are two major determinants of gastric cancer, while gastroesophageal reflux and obesity have been linked to Barrett’s esophagus, a known precursor of esophageal adenocarcinoma. The use of high-tech diagnostic methods developed in recent years has made screening and diagnosis of these diseases easier. These technologies, together with strategic screening of high-risk populations have enabled earlier detection of neoplastic lesions to allow more timely intervention of the disease process. On the other hand, newer, less invasive endoscopic and surgical intervention techniques are making radical changes towards better management of the diseases, right from pre-neoplasia stage. This article will review the diagnosis and management of these diseases in the light of current clinical practices.