A 34-year-old male patient with epigastralgia was found to have an esophageal submucosal tumor based on an endoscopic evaluation 6 years previously. Because an unusual appearance composed of a heterogeneous solid area and a cyst area on the endoscopic ultrasonogram and the increased size of the tumor on esophagograms over the past 3 years were suggestive of a malignant character, an operation was thus indicated. The tumor, which measured 3.5 x 2.5 x 2.0 cm in size, was enucleated using videoassisted thoracic surgery and was diagnosed to be a very rare myxoid leiomyosarcoma with a thorough pathologic examination. To our knowledge, this is only the second case of esophageal myxoid leiomyosarcoma reported in the literature. We thus consider this case, which demonstrated an unique appearance on an endoscopic ultrasonogram, to possibly be beneficial to the overall diagnostic analysis of esophageal submucosal tumors.