In recent years, the press has reported on poison attacks on double agent Sergei Skripal, Russian opposition figure Alexei Navalny and the half-brother of North Korean dictator Kim Jong-un. What all three attacks have in common is that they were carried out with so-called nerve agents. This lecture deals with the background to the three attacks and the evidence that helped to solve them. In this context, the mode of action of nerve agents and their significance as chemical weapons will be explained and the work of the Organization for the Prohibition of Chemical Weapons will be presented.