We report our findings on the clinical efficacy and impact of using the Guidelines for the Diagnosis and Treatment of Esophageal Cancer after inquiry-based research involving the council members of the Japan Esophageal Society. The majority of the 145 respondents were esophageal surgeons with more than 20 years' experience at university hospitals or major clinical centers throughout Japan. They generally treated esophageal cancer following the guidelines. Although each surgeon makes his or her own judgment in each case, they reported that they experienced less stress when using the guidelines, or more stress when using non-standard treatment deviating from the guidelines. A key finding was that the guidelines were overly complex and difficult to understand concerning informed consent, especially by patients. Only one-half of the respondents followed the guidelines when obtaining informed consent, because they are too difficult and vague for patients to understand. The guidelines should therefore be revised and improved in this aspect.