The principal aim of the International Conference on Nuclear Security: Global Directions for the Future was to share information on how to most successfully combat sub-State and criminal threats now and in the future, and to foster a better understanding and awareness of the global changes since 11 September 2001. The conference considered the threat of malicious acts involving nuclear and other radioactive material; the experiences, achievements and shortcomings of national and international efforts to strengthen the prevention of, detection of and response to malicious acts involving these materials; and the ways and means to achieve future improvements. These proceedings contain the opening and keynote addresses and the invited papers presented during the various topical and panel sessions. The conference generated an extensive exchange of information on key issues related to a number of aspects of nuclear security. The summaries of these discussions, as well as the findings, as presented by the President of the Conference, are also included.