This article tells the story of how and why legislative candidate sex quotas, more commonly known as gender quotas, were adopted by the Irish Parliament in July 2012. In so doing, it reviews both internal party equality strategies and external party influences. Tracing party data over a two-decade period, the article shows that parties have adopted a range of strategies, in line with their ideological orientation, to address women's political under-representation. For the most part, however, these strategies have been rhetorical and promotional in nature, and have not resulted in significant gains for women in electoral politics. To understand how support for gender quotas was secured, Krook's analytical framework for the adoption of gender quotas is employed, and the conditions favouring the introduction of quotas in Ireland are identified. The article finds that the coming together of a constellation of pressures, notably a political reform discourse, the mobilisation of civic society groups and elite support, facilitated the adoption of legislative candidate sex quotas in 2012, a legislative outcome that could not have been predicted some years earlier.