The article presents Qualitative Comparative Analysis (QCA) as a method for innovation research. Based on set-theory, a key feature of QCA is the possibility to examine the necessary and the sufficient conditions for the institutionalisation of innovations. QCA aims to identify equifinal explanations for a social phenomenon, which consist of a combination of several conditions. This approach distinguishes QCA from qualitative and quantitative methods. Furthermore, QCA combines a comparative and a case-oriented approach, which is especially interesting for the analysis of innovations as context-sensitive and contingent phenomena. QCA as a research approach and method is outlined briefly, with special regard to the tasks of innovation research. Its application is presented in a study of the conditions for equal pay regulations in OECD countries. The analysis shows that the relevant actors for the institutionalisation of equal pay regulations are either women’s movements or unions but that neither are solely sufficient for this legal innovation. Instead QCA also captures the context conditions for their impact on the enactment of equal pay regulations.