pharmacological-type agents, such as Clostridium botulinum toxin injection or calcium channel blockers.3–7 An innovative endoscopic method for dissection of the LES, using a needle-knife to cut the muscular fibers from the lumenal side, was first described by Ortega et al.8 in 1980. Two decades later, Pasricha et al.9 first described the feasibility of an endoscopic submucosal esophageal myotomy in a survival animal model. Finally, Inoue et al.10 successfully performed the first peroral endoscopic esophageal myotomy (POEM) in humans, which appeared to be substantially less invasive, when compared with LHM. Following this preliminary experience, there have been published in the last years a number of prospective and retrospective experiences with POEM for achalasia, with controversial data in terms of adverse events and outcome. The aim of this systematic review was to pool the results of POEM procedures, in terms of efficacy and safety, and also address relevant clinical and technical issues.