AIM: To investigate whether magnifying endoscopy with narrow band imaging (ME-NBI) is useful for evaluating the area of superficial, depressed- or flat-type differentiated adenocarcinoma of the stomach. METHODS: This procedure was performed in Saitama Medical University International Medical Center, Japanese Red Cross Kumamoto Hospital and Kitakyushu Municipal Medical Center. The subjects were 31 patients in whom biopsy findings, from superficial, depressed- or flat-type gastric lesion, suggested differentiated adenocarcinoma in the above 3 hospitals between January and December 2009. Biopsy was performed on the lesion and non-lesion sides of a boundary (imaginary boundary) visualized on ME-NBI. The results were pathologically investigated. We evaluated the accuracy of estimating a demarcation line (DL) on ME-NBI in comparison with biopsy findings as a gold standard. RESULTS: The DL that could be recognized at 2 points on the orifice and anal sides of each lesion during ME-NBI was consistent with the pathological findings in 22 patients with 0-Ⅱc lesions, 7 with 0-Ⅱb lesions, and 2 with 0-Ⅱb + Ⅱc lesions, showing an accuracy of 100%. CONCLUSION: The results suggest the usefulness of ME-NBI for evaluating the area of superficial, depressed- and flat-type differentiated adenocarcinoma of the stomach. AIM: To be considered magnifying endoscopy with narrow band imaging (ME-NBI) is useful for evaluating the area of ​​superficial, depressed- or flat-type varyed adenocarcinoma of the stomach. METHODS: This procedure was performed in Saitama Medical University International Medical Center , Japanese Red Cross Kumamoto Hospital and Kitakyushu Municipal Medical Center. The subjects were 31 patients in whom biopsy findings, from superficial, depressed- or flat-type gastric lesion, suggested differentiated adenocarcinoma in the above 3 hospitals between January and December 2009. Biopsy was Perform on the lesion and non-lesion sides of a boundary (imaginary boundary) visualized on ME-NBI. The results were pathologically investigated. We evaluated the accuracy of estimating a demarcation line (DL) on ME-NBI in comparison with biopsy findings as a gold standard. RESULTS: The DL that could be be recognized at 2 points on the orifice and anal sides of each damage during the ME-NBI was cons Istent with the pathological findings in 22 patients with 0-IIc lesions, 7 with 0-IIb lesions, and 2 with 0-IIb + IIc lesions, showing an accuracy of 100%. CONCLUSION: The results suggest the usefulness of ME-NBI for Evaluating the area of ​​superficial, depressed- and flat-type differentiated adenocarcinoma of the stomach.