Gastroesophageal junction carcinoma is a rare but often lethal condition with increasing importance as a public health problem in recent decades. While diagnosis of this disease has been complicated historically by the lack of uniform classification standards, available data from the Surveillance, Epidemiology, and End Results (SEER) cancer registry program in the United States show an approximate 2.5-fold increase in the incidence of gastroesophageal junction adenocarcinoma (GEJAC) from 1973–1992, with rates stabilizing in the last two decades. Similar proportional trends are observed among subgroups defined by race and gender, but rates are significantly higher in males relative to females, and in white males relative to black males. Smoking, obesity, and gastroesophageal reflux disease are significant risk factors for GEJAC, and may account for a substantial fraction of total disease burden. Infection with Helicobacter pylori has been associated with reduced incidence, and high dietary fiber intake has also been linked to lower disease risk. Ongoing studies continue to explore a potential role for non-steroidal anti-inflammatory drugs in chemoprevention.