Research objective: Blood donation is still the main source of blood and blood products in the world. The goal of the research was to develop and validate the Blood Donor Motivation and Satisfaction Questionnaire (MZDK), and with the control of sociodemographic characteristics, examine potential personal and psychological predictors and satisfaction with the service in explaining the intrinsic and extrinsic motivational aspects of the intention to donate blood. The assumption is that the intention to donate blood again is related to personal and psychological factors and different aspects of service satisfaction. Study design: The research is designed as a cross-sectional study. It was carried out in two parts. The first part was the development and validation of the instrument (MZDK), and in the second part, with the help of the validated MZDK questionnaire, potential predictors of the intention to donate blood again were examined. Subjects and methods: Subjects (n = 928) were voluntary blood donors who came to the Clinical Institute for Transfusion Medicine of the Clinical Hospital Center Osijek to donate whole blood or a blood component. A questionnaire consisting of three parts was used as a research instrument: general and demographic characteristics, previous blood donation experience, and a validated multidimensional questionnaire MZDK. Results: A new instrument with seven scales was constructed and validated, with good metric characteristics (the internal reliability coefficient Cronbach α ranges from 0.721 to 0.962). Hierarchical multivariate regression analysis (with the control of sociodemographic characteristics) in the explanation of the intrinsic motivation of the intention to donate blood is significant predictors satisfaction with the service of the institution and religiosity, and in the explanation of the extrinsic motivation of the intention to donate, male gender and greater discomfort during blood donation. Conclusion: Satisfaction with the institution's service, religiosity, gender and discomfort during donation are significant predictors of the intention to donate blood again. The psychometrically created and validated instrument MZDK will enable future evaluations of satisfaction with the service and factors for the purpose of retaining current, encouraging new, and future potential blood donors.