Sarin is a potent nerve agent chemical weapon that was originally designed for military purposes as a fast-acting anti-personnel weapon that would kill or disable large numbers of enemy troops. Its potent toxicity, ease of deployment, and rapid degradation allow for rapid deployment by an attacking force, who can safely enter the area of deployment a short while after its release. Sarin has been produced and stockpiled by a number of countries, and large quantities of it still exist despite collective agreements to cease manufacture and destroy stockpiles. Sarin’s ease of synthesis, which is easily disseminated across the Internet, increases the risk that terrorist organizations may use sarin to attack civilians. Sarin has been used in a number of terrorist attacks in Japan, and more recently in attacks in the Middle East, where nonmilitary organizations have led much of the disaster relief and provision of medical care. In the present article, we examine and discuss the available literature on sarin’s historical use, delivery methods, chemical properties, mechanism of action, decontamination process, and treatment. We present a management guideline to assist with the recognition of an attack and management of victims by medical professionals and disaster relief organizations, specifically in resource-constrained and austere environments. (Disaster Med Public Health Preparedness. 2018;12:249–256)