In this article, we explore the impact of intra-party democratization processes on party membership. We analyze the opinions and attitudes of enrolled members on intra-party democracy instruments and on the use of open primaries. We investigate, with original data sets on Italy, the relationship between primaries and party members. How do enrolled members perceive internal democratization and primaries? Which factors contribute to explaining grassroots members’ opinion on primaries? We use the case of the Italian Democratic Party (PD) to argue that different subsets of the party membership (divided into new-style and old-style members, on the basis of their relationship with the party and their participatory style) have different views on primaries. Quantitative analysis of survey data on party members reveals two main findings. Our first result is that members approve and positively assess the adoption of new procedures of intra-party democracy. Second, membership style matters: old-style members react to the adoption of primary elections differently than new-style members. Indeed, old-style members understand primaries as a renovated chance of participating in the party’s activities, whereas for new-style members primaries give the opportunity for a new mode of participation. Our findings contribute to the existing empirical research on intra-party democracy and party membership, and have important implications for the triangular link between parties, members and primaries.