We reviewed the history of the registry of esophageal cancer cases in Japan.The Registration Committee for Esophageal Cancer, the Japan Esophageal Society, has annually registered cases of esophageal cancer since 1976 and published the first issue of the Comprehensive Registry of Esophageal Cancer in Japan in 1979.The Act for the Protection of Personal Information was promulgated in 2003, and began to be enforced in 2005.The purpose of this Act is to protect the rights and interests of individuals while taking into consideration the usefulness of personal information, keeping in mind the remarkable increase in the use of personal information arising from the development of todays advanced information and communications society.The registry of esophageal cancer cases has required some adjustments to comply with the Acts.The new registration system has been discussed for several years and was finally completed in 2008.The most important point was "anonymity in an unlinkable fashion" using encryption with a hash function.Finally, the registry resumed registering cases of esophageal cancer that had been treated in 2001.We summarized the Comprehensive Registry of Esophageal Cancer in Japan, from 2001 to 2003.A total of 12,880 cases were registered in Japan.As for the histologic type of cancer according to biopsy specimens, squamous cell carcinoma and adenocarcinoma accounted for 91.7% to 92.2% and 2.3% to 3.0%, respectively.Regarding clinical results, the 5-year survival rates of patients treated using endoscopic mucosal resection and esophagectomy were 80.0% to 87.7% and 42.6% to 46.6%,respectively.We hope that this Comprehensive Registry of Esophageal Cancer in Japan helps to improve all aspects of the diagnosis and treatment of esophageal cancer.