States parties to the Chemical Weapons Convention (CWC) have agreed among themselves to prohibit the development, production, and use of chemical weapons (CW) and ensure their destruction. During its first 25 years of operation the focus of the CWC and the Organization for the Prohibition of Chemical Weapons (OPCW), which has been set up to oversee its implementation, has been on the destruction of state-level CW arsenals. Yet, ever since the September 11 attacks in 2001, the specter of chemical terrorism has influenced the OPCW in the performance of several of its functions. Given its origins at the end of the Cold War, with a concomitant focus on state-level CW programs, we ask what role the CWC has played in the global fight against terrorism. To this end, the first section of the paper outlines key provisions of the CWC, functions of the OPCW, and their relevance in the fight against CW terrorism. We then address the mandate of the United Nations for fighting terrorism, as contained in its Global Counterterrorism Strategy and Security Council Resolution 1540, and its relationship agreement with the OPCW. Subsequent sections analyze practical cooperation measures in the areas of assistance, protection and capacity building, and in verifying compliance with the CWC. The final section draws together the argument and provides an assessment of CWC and OPCW in supporting the global fight against terrorism.