A case of endoscopically resected early esophageal carcinoma associated with achalasia is reported. A 63-year-old woman was made diagnosis of esophageal achalasia, sigmoid type and grade III. The patient was operated by Tokai University method, Heller's long esophagomyectomy, Hill's posterior cardiopexy, fundoplication and selective proximal vagotomy using a laparotomy. Two years and six months after the operation, an early carcinoma of type 0-IIb, 1cm in size, was detected in the upper thoracic esophagus, and treated by endoscopic mucosal resection using EEMR-tube method. Pathological examination revealed proliferation of squamous cell carcinoma in situ (Tis: m1). The entire esophageal mucosa around the carcinoma demonstrated hyperplastic changes of stratified squamous epithelium and foci of dysplastic changes. In the patient of achalasia, food stasis in esophagus is thought to induce chronic hyperplastic esophagitis, converting eventually to malignant transformation. Achalasia is known as a risk factor of esophageal carcinoma. Early operation or good drainage of the esophageal lumen might reduce the risk. Long-term follow-up for patients of achalasia by endoscopic screening is recommended.