Peroral endoscopic myotomy (POEM) was developed by our group to provide a less invasive permanent treatment for esophageal achalasia. POEM was performed in 17 consecutive patients with achalasia (10 men, 7 women; mean age 41.4 years). A long submucosal tunnel was created (mean length 12.4 cm), followed by endoscopic myotomy of circular muscle bundles of a mean total length of 8.1 cm (6.1 cm in distal esophagus and 2.0 cm in cardia). Smooth passage of an endoscope through the gastroesophageal junction was confirmed at the end of the procedure. In all cases POEM significantly reduced the dysphagia symptom score (from mean 10 to 1.3; P = 0.0003) and the resting lower esophageal sphincter (LES) pressure (from mean 52.4 mmHg to 19.9 mmHg; P = 0.0001). No serious complications related to POEM were encountered. During follow-up (mean 5 months), additional treatment or medication was necessary in only one patient (case 17) who developed reflux esophagitis (Los Angeles classification B); this was well controlled with regular intake of protein pump inhibitors (PPIs). The short-term outcome of POEM for achalasia was excellent; further studies on long-term efficacy and on comparison of POEM with other interventional therapies are awaited. Georg Thieme Verlag KG Stuttgart. New York.