In focusing on characteristics of national cabinets and parliaments, this paper seeks to understand domestic factors that are conducive to the enforcement of policies which protect victims of human trafficking in 33 democratic member countries of the European Union (EU) and the Organisation for Economic Co-Operation and Development (OECD). It argues for the need to consider the role of policymakers when trying to understand what drives the implementation and enforcement of international treaties that combat organized crime, such as the United Nations Protocol to Prevent, Suppress and Punish Trafficking in Persons, Especially Women and Children, in national policies. In so doing, the paper applies theoretical arguments of comparative politics to criminology. Multivariate analyses show that the share of female parliamentarians and the proportion of left wing and social democratic parties in cabinet are significantly and positively associated with stronger efforts to protect victims of human trafficking. Future research should expand the insights of this analysis through case studies on parliamentary behaviour, legislative proposals, and votes related to human trafficking.