Smooth muscle tumors presenting as mediastinal soft tissue masses are rare and are often mistaken for other neoplasms. Benign tumors of the esophagus account for fewer than 1% of all esophageal tumors, the most common of which are leiomyomas. They are frequently located in the lower third of the esophagus. We report two cases of esophageal leiomyoma in the thoracic esophagus which were firstly presented as huge mediastinal mass with intermittent dysphagia and radiologically flecks of calcification.