Accurate mapping of colorectal neoplasms is needed in many clinical situations. Intraoperative mapping of small lesions previously detected by endoscopy is often challenging, especially during laparoscopic surgery. Tumor location assessed during colonoscopy may be inaccurate because of limitations of the procedure. Small flat neoplasms with signs of invasiveness, which are hard to detect by palpation, hold a special place. The same situation is observed for nonradical endoscopic resection of malignant polyps or early cancer, when visual examination shows that the tumor masses have been completely resected but histological examination reveals the positive lateral or horizontal resection margin. Endoscopic tattooing is an effective, safe, and economically sound method to mark intraluminal colorectal neoplasms, which allows one to perform minimally invasive surgeries without using additional operating room resources.