The word achalasia is a neologism of Greek origin, coined by the English physician Sir Edwin Cooper in 1913, and means no quality of relaxation. Achalasia is a disease clinically manifested by dysphagia with both solids and liquids, esophageal regurgitation, retrosternal pain, cough, bronchial aspiration, pneumonia, heartburn and weight loss. Physiopathologically it corresponds to the loss of esophageal peristalsis and to an insufficient relaxation of the lower esophageal sphincter (LES). These motor abnormalities are due to the loss of myenteric neurons that coordinate esophageal peristalsis and relaxation of the LES. First described by Sir Thomas Willis in 1674, and although it is currently considered idiopathic, it has begun to be considered as possible causes autoimmune components and genetic predisposition; viral infections by herpes and chickenpox zoster have also been implicated as probable causes.Its incidence ranges from 0.3 to 1.63 per 100,000 adults, with a prevalence of 10 in 100,000 inhabitants per year. It affects equally any gender, and the age group between 30 and 60 years is the most affected. The diagnosis is suspected based on the symptomatology, with dysphagia being the most important symptom. It is confirmed with the performance of endoscopy of the upper digestive tract, esophagogram and high resolution manometry. The treatment remains palliative, and may be guided by the subtype of achalasia, according to the Chicago classification. The best results are obtained by the techniques of pneumatic dilation, Heller’s laparos- copic myotomy, and more recently by the POEM technique (per oral endoscopic myotomy), described in 2008 in Japan by Haruhiro Inoue. There is still a lack of prospective randomized studies with long-term follow-up that determine which is the best technique. An updated review of the subject is presented. Fecha de recibido: 12/09/2018 – Fecha aceptacion: 16/11/2018