Endoscopic tattooing with Indiaink is generally regarded as a safe procedure that enables ready identification of endoluminal cancer from the serosal surface. However, significant complications have been reported, including local inflammatory pseudotumor formation, peritonitis, rectus muscleabscess, small bowel infarction, and phlegmonous gastritis. Although the mechanism of complication is not completely understood, it may be related to the chemical compounds contained in the inksolution and enteric or extraenteric bacterial inoculation by injectionneedle or the ink itself. Authors encountered a case of a 60-year-old man with a resectable sigmoid colon cancer which was tattooed with Indiaink for subsequent localization in the intraoperative setting. During the laparoscopic operation, the proximal and distal margin of the lesion appeared edematous with bluish color. The distal resection margin was extended approximately 5 cm more than expected because of long extent of edematous mucosa. Histologic examination of the edematous tattooing area revealed an inkabscess spreading laterally above the muscularis propria. Although tattooing is widely used and relatively safe, the presented case indicates the risk of infection or inflammation by tattooing.