PURPOSE OF THE REVIEW: Peroral endoscopic myotomy (POEM) is a novel minimally invasive technique that has emerged as the preferred option for the treatment of achalasia and spastic esophageal disorders (SED) at many centers around the world. In this article, we review and summarize the recent literature on POEM in patients with achalasia and SED. The current article is largely focused on the new developments and findings, extended applications, and long-term outcomes of POEM in patients with achalasia and SED.