Recently, prone position esophagectomy for esophageal cancer is thought to be an easier and safer procedure. Here, we introduced prone position for enucleation of the fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) positive esophageal leiomyoma. The patient was a 47-year-old man with a 4 cm mid-thoracic esophageal submucosal tumor. The tumor was enucleated safely without injury of the esophageal mucosa under the gravity effect of the prone position with use of a sponge spacer and Sengstaken-Blakemore balloon. Postoperative examination revealed that the tumor was a leiomyoma that was positive for smooth muscle actin and negative for CD117. Postoperative course was uneventful and the patient was discharged on day 7 after the operation. The prone position with use of a sponge spacer and Sengstaken-Blakemore balloon was a safer and easier procedure for the enucleation of the esophageal submucosal tumor.