Blood donations are essential for many routine medical procedures and the development of plasma-derived medicinal products. Donor retention poses a major challenge for blood collection, because many donors lapse after having made only few donations. In previous research, blood donors are typically treated as a homogeneous group, which limits both our theoretical understanding of donor behaviour and the effectiveness of interventions aimed at donor retention. In this study, we aim to identify types of blood and plasma donors based on factors that have been identified as central drivers of repeated blood donation behaviour, including constructs from an extended Theory of Planned Behaviour, prosocial values, and social network characteristics. We apply latent transition analysis to a large sample of blood and plasma donors in the Netherlands (N = 22128). We identify 4 classes of donors: the balanced donors (33%), the exceptionally motivated donors (18%), the unfulfilled donors (23%), and the confident habitual ...