There are no previous reports of Mallory-Weiss tears occurring as complications during esophageal endoscopic submucosal dissection (ESD). We present 3 cases of Mallory-Weiss tears occurring during treatment of superficial squamous cell neoplasms through ESD. Carbon dioxide was used for air insufflation, and the patient was adequately sedated without retching or struggling during the operation. No significant bleeding from the lesion was observed during ESD; however, active bleeding caused by the Mallory-Weiss tear was identified endoscopically. Bleeding was controlled by closure of the tear with metal clips or repeated flushing with adrenaline saline. Hemorrhage did not recur until completion of the operation. Therefore, during the operation, it is necessary to maintain adequate depth of anesthesia and reduce the operation time, and also reduce air and water injections, to avoid occurrence of such complications.