This paper brings together insights from feminist and new institutional theory to explore and understand the gendered dynamics of innovation and change in the candidate selection process. Building on the conventional supply-and-demand model of political recruitment, the paper argues for a more dynamic framework that takes into account how the institutions of recruitment change over time, while also acknowledging the ways in which ‘old’ gender practices, norms and expectations can serve to dilute the impact of candidate selection reforms (Kenny, 2013; see also Mackay, 2009; Chappell, 2011). Drawing on original empirical research on candidate selection reform and constitutional change in post-devolution Scotland, the paper argues that institutional innovation in political recruitment is a contested process, shaped by multiple, and often competing, interests, motivations and gendered power differentials. It also draws attention to the ways in which the complex and contingent interaction between diverse institutional elements – old and new, formal and informal – both enable and constrain attempts at institutional reform. These findings highlight the complex dynamics of institutional design, continuity and change in the recruitment process and provide further insights into the general and gendered difficulties of reforming recruitment in the face of powerful institutional and gendered legacies.