Incorporating the social differentiations of gender, race, disability, sexual orientation, religion or belief, and age into UK equal opportunities and diversity legislation involved creating a new single equality body for Great Britain (England, Scotland, and Wales). This paper assesses the efficacy of an Equality and Diversity Mainstreaming approach established in Northern Ireland (NI) for this new agency. It also stresses the potential value of “intersectionality” to further policy planning and development. It is argued that the combination of the NI model underpinned by the concept of intersectionality could offer a way forward for the new agency where, importantly, the issue of gender remains one of the most important axes of domination. Copyright © 2010 ASAC. Published by John Wiley & Sons, Ltd.