Achalasia is a rare neurological deficit of the esophagus that produces an impaired relaxation of the lower esophageal sphincter and decreased motility of the esophageal body. Achalasia is generally accepted to be a pre-malignant disorder, since, particularly in the mega-esophagus, chronic irritation by foods and bacterial overgrowth may contribute to the development of dysplasia and carcinoma. We present a case of a 51-year-old man with achalasia combined with esophageal cancer who has had dysphagia symptoms for more than 20 years. Since there was a clinically high possibility of supraclavicular lymph node metastasis, concurrent chemoradiation therapy was scheduled. After the third cycle of chemoradiation therapy, transthoracic esophageolymphadenectomy was performed. Histopathological examination of the main esophagus specimen revealed no residual carcinoma. And the entire regional lymph node areas were free of carcinoma except for one azygos metastatic lymph node. In summary, achalasia is a predisposing factor for esophageal squamous cell carcinoma. Although surveillance endoscopy in achalasia patients is still controversial, periodic screening for cancer development in long-standing achalasia patients might be advisable