The basic principle behind the treatment of achalasia consists of alleviating swallowing disorders by reducing resistance in the lower esophageal sphincter without inducing gastroesophageal reflux. Only a few studies are available on long-term results after operative treatment. Fifty-one patients were studied with regard to long-term results after open transabdominal extramucosal myotomy of the distal esophagus along with partial anterior fundoplication (Dor procedure). Clinical data were collected by standardized interviews, and symptoms were assigned a score ranging from 0 to 3 according to severity and frequency. The pre- and postoperative symptoms were comparable in 50 patients. The median duration of follow-up was 88 months (range: 12-160 months). Operative time was a median of 80 min. Two esophageal mucosal tears were recognized intraoperatively and promptly repaired. Postoperative morbidity occurred in two patients (3.9%). Very good or good long-term results after surgical therapy were achieved in 49 patients (96.1%). Forty-seven patients (92.2%) have no or rare dysphagia. The frequency of regurgitation as well as chest pain was also significantly reduced after surgery. Forty-nine patients (96.1%) either maintained or gained weight. Preoperative duration of symptoms, follow-up, age, and gender had no influence on the results (p > 0.05). Two patients (3.9%) mentioned occasional heartburn. Five patients (9.8%) took or still take proton pump inhibitors postoperatively. Severe stage IV symptoms due to peptic stricture and dolichomegaesophagus required reoperation in one patient (2%). The results show that myotomy and the antireflux procedure (semifundoplication) lead to long-term relief of dysphagia without inducing reflux at a low operative risk. Since long-term results are as yet not available for minimally invasive surgery, it remains to be seen if this operative technique will become the primary surgical procedure for this disease.