Achalasia is a primary esophageal motility disorder of unknown etiology, characterized by aperistalsis of the esophageal body and impaired lower esophageal sphincter (LES) relaxation. However achalasia is the best characterized esophageal motility disorder, its pathogenesis is still not entirely clarified. Available data suggest that the disease is mul- tifactorial, involving hereditary, autoimmune and environmental factors, such as viral infections, but the exact initiating factors that may play a role in the development of the disease remain unclear. Our hypothesis is that one possible initial insult that leads to the development of achalasia can be the gastroesophageal reflux disease. This theory was first proposed by Smart et al. in 1986. In our case study we report the case of a 65-year-old woman who had typical reflux symptoms with heartburn and regurgita- tion for about seven years. During the year before her admission to our clinic her reflux symptoms resolved and dysphagia developed. Endoscopy revealed esophageal dilatation with erosive esophagitis, narrowed cardia and hiatal hernia. Biopsies from the distal esophagus showed chronic esophagitis and Barrett’s metaplasia. Barium swallow showed dilated esophageal body with decreased peristalsis, nonrelaxing sphincter and retention of barium. Manometry and 24-hour pH monitoring was per- formed. The LES pressure was 34.5 mmHg with 11.9% relaxation. 24-hour pH-metry showed acid reflux, with multiple sharp dips characteristic of typical gastroesophageal reflux, with total DeMeester score of 94.6. Using pH 3 as a discriminatory threshold for GERD the reflux score was 64.2. Achalasia and concomitant GERD was diagnosed and the patient under- went laparoscopic surgery. The hiatal hernia was reconstructed and a Heller’s myotomy with a 360 degree Nissen fundoplication was per- formed. At the 3-year follow-up the patient was symptom free. In sum- mary, based on our experience and the review of the literature we believe that there is a cause-and-effect relationship between gastroesophageal reflux and the development of achalasia. We believe that the develop- ment of achalasia in patients with GERD can be a protective reaction of the esophagus against reflux. In these cases the treatment of choice should be different from that of pure achalasia patients: a laparoscopic Heller’s myotomy completed with a 360 degree Nissen fundoplication should be the recommended surgical treatment to minimize the possi- bility of postoperative reflux disease.