Today there are millions of reported cases of missing and disappeared persons from armed conflict and human rights abuses around the world. In addition, thousands of persons go missing every year as a result of disasters, human trafficking, organized violence and other causes. Developments in the last two decades have seen an evolution in how the issue of the missing has been addressed, particularly following conflicts and disasters. Because of this, the scale of the problem has become better known, guidelines, standards and policies on the missing are being more efficiently defined, and advances in science and informatics now make it possible to locate the missing more effectively than ever before. Still, the extent to which these new capabilities are applied continues to depend on the circumstances under which a person has gone missing, as well as on who is searching for that person and to what end. To provide effective guarantees against persons going missing and to safeguard the rights of relatives of the missing, it is necessary to look beyond traditional categorisations and to view the issue as an integral part of human rights and human security. Providing effective redress to the problem of the missing must, therefore, form part of a more broadly comprehensive global effort to reduce human vulnerability, enhance political participation and expand access to justice and economic rights.