Esophageal achalasia is a disease with characteristic disorder of esophageal motility. Also, this disorder is known to be predisposing factor of malignancy. Although the incidence of esophageal cancer in patients with achalasia varies widely, the incidence hed been reported from l% to 29% in many articles. It is known that delay in management of achalasia is believed to increase the risk of malignant degeneration. We experience a case with esophageal cancer complicating longstanding esophageal achalasia.