We estimated the prevalence and prognostic significance of neuroendocrine (NE) cells in a series of 208 resection specimens containing gastroesophageal junction (GEJ) adenocarcinomas, with 56 specimens containing Barrett's mucosa. Immunohistochemically, chromogranin A (CGA) was positive in 49% (102/208) of GEJ adenocarcinomas and in 68% (38/56) of Barrett's mucosas. CGA in GEJ tumors correlated with pTNM stage. CGA in Barrett correlated with pTNM stage and tumor grade of the adjacent carcinoma. Patients with CGA in Barrett had better survival than patients without CGA in Barrett, with 5-year survival percentages of 56% and 9%, respectively. In multi-variate analysis, CGA in Barrett was an independent prognostic factor for survival after surgery. Therefore CGA in Barrett adjacent to GEJ adenocarcinoma might be helpful in the assessment of patient outcome.