Achalasia is a rare motility disorder of the esophagus characterized by the absence of peristalsis and defective relaxation of the lower esophageal sphincter. Patients present at all ages with dysphagia and regurgitation as main symptoms. The diagnosis is suggested by barium swallow and endoscopy and confirmed by manometry. Because there is no curative treatment for achalasia, treatment is confined to disruption of the lower esophageal sphincter to improve bolus passage. The most successful therapies are pneumodilation and laparoscopic Heller myotomy, with comparable short-term clinical rates of success. The prognosis of achalasia patients is good, but re-treatment is often necessary.