A 75-year-old man underwent endoscopic hemostatic therapy for hemorrhagic gastric ulcer in September 2002. After healing of the gastric ulcer, he underwent Helicobacter pylori eradication therapy in February 2003. In August 2007, an irregular tumor was detected in the lower esophagus at annual checkup for gastric cancer screening using X-ray. Endoscopic examination showed that the lower margin of the tumor almost coincided with the esophagogastric junction and that a short segment of Barrett's epithelium existed near the tumor. Biopsies of the tumor showed moderately to poorly differentiated adenocarcinoma. Mild reflux esophagitis and minor hiatal hernia was also observed, and the previously treated gastric ulcer was not recurrent. Absence of H. pylori was confirmed by serum antibody and urea breath test. Surgical resection of the lower esophagus and proximal stomach was performed. The tumor invaded into the muscularis propria of the esophageal wall but had no evidence of lymph node metastasis. Based on macroscopic and pathological findings, the tumor was recognized as esophageal adenocarcinoma. Previous endoscopic examination did not detect any apparent signs of tumor in the esophagogastric junction. As far as we know, this is the first report documenting a newly developed esophageal adenocarcinoma after the successful eradication of H. pylori.