Abstract This paper explores why the signature record of the International Convention on the Protection of Rights of All Migrant Workers and Members of Their Families has been so poor, especially among the Organisation for Economic Co-operation and Development (OECD) democracies. It does so by examining two kinds of explanations. The first suggests that the international campaign to promote the treaty was weak. The second concerns the treaty design: states dislike this treaty because of its complexity, precision, and the lack of national security ‘escape clauses’. This study finds that the strength of the international campaign does not correlate with participation in human rights treaties. It also uncovers an inherent flaw in the design-based explanations and strongly suggests that we look elsewhere for the causes of the ‘failure’ of this treaty.