The Illicit nuclear trafficking panel was conducted at the 4th Annual INMM workshop on Reducing the Risk from Radioactive and Nuclear Materials on February 2-3, 2010 in Washington DC. While the workshop occurred prior to the Nuclear Security Summit, April 12-13 2010 in Washington DC, some of the summit issues were raised during the workshop. The Communique of the Washington Nuclear Security Summit stated that 'Nuclear terrorism is one of the most challenging threats to international security, and strong nuclear security measures are the most effective means to prevent terrorists, criminals, or other unauthorized actors from acquiring nuclear materials.' The Illicit Trafficking panel is one means to strengthen nuclear security and cooperation at bilateral, regional and multilateral levels. Such a panel promotes nuclear security culture through technology development, human resources development, education and training. It is a tool which stresses the importance of international cooperation and coordination of assistance to improve efforts to prevent and respond to incidents of illicit nuclear trafficking. Illicit trafficking panel included representatives from US government, an international organization (IAEA), private industry and a non-governmental organization to discuss illicit nuclear trafficking issues. The focus of discussions was on best practices and challenges for addressing illicit nuclear trafficking. Terrorism connection. Workshop discussions pointed out the identification of terrorist connections with several trafficking incidents. Several trafficking cases involved real buyers (as opposed to undercover law enforcement agents) and there have been reports identifying individuals associated with terrorist organizations as prospective plutonium buyers. Some specific groups have been identified that consistently search for materials to buy on the black market, but no criminal groups were identified that specialize in nuclear materials or isotope smuggling. In most cases, sellers do not find legitimate buyers; however, there have been specific cases where sellers did find actual terrorist group representatives. There appears to be a connection between terrorist groups engaged in trafficking conventional arms and explosives components that are also looking for both nuclear materials and radioisotopes. Sale opportunities may create additional demand for such materials. As we can observe from Figure 1, many cases in the mid-90s involved kilogram quantities of material. There were smaller amounts of material moved in 2001, 2003 and 2006. While we have seen less trafficking cases involving PujHEU in recent years, the fact that it continues at all is troubling. The trafficking cases can be presented through their life cycle: Diversion of materials leads to Trafficker and then to Terrorist/Proliferator. Most of the information we have in trafficking cases is on the Trafficker. In 16 cases reported by the IAEA, there are 10 prosecutions of the involved trafficker. However, there are no confirmed diversions of material recorded in any of the 18 seizures. Most seizures were sting operations performed by law enforcement or security agents with no actual illicit end-user involved.