Endoscopic submucosal dissection has been a useful treatment of selected colorectal neoplasia cases. The incidence of perforation related to colorectal endoscopic submucosal dissection is 5-20%. However, while there have been numerous reports regarding retroperitoneal, mediastinal, pleural and subcutaneous emphysema after therapeutic colonoscopy, pneumoscrotum is a relatively rare manifestation of perforation associated with colorectal endoscopic submucosal dissection. In particular, pneumorrhachis, or air within the spinal cord, following therapeutic colonoscopy, is extremely rare. Herein, we report a conservatively treated perforation case as having pneumorrhachis, penumoscrotum, and pneumoperitoneum after colorectal endoscopic submucosal dissection.