Introduction: In the Netherlands, there is a constant shortage in donor organs, resulting in long waiting lists. The decision to register as organ donor is associated with several demographic, cultural, and personal factors. Previous research on attitudes and motivations toward blood and organ donations provided similar results. Research Question: The current study investigated demographic, cultural, and personal determinants of organ donation registration among current Dutch blood donors. Design: We used data from Donor InSight (2012; N = 20 063), a cohort study among Dutch blood donors, to test whether age, gender, religious and political preferences, donor attitude, and altruism predicted organ donor registration among current blood donors. Results: Organ donors were more often represented in the blood donor population compared to the general Dutch population. Women showed a higher propensity to be registered as organ donor. Higher education as well as higher prosocial value orientation, prosocial behavior, that is, doing volunteer work, and awareness of need significantly associated with being registered as organ donor. Religious denomination negatively predicted organ donation registration across all faiths. Discussion: Results are discussed in light of cultural context, and possible implications for improving information provision and recruitment are mentioned.