Worldwide, demand for blood and blood products has increased. It is important to work on donor recruitment strategies. Because in developed countries the young have been more reluctant to donate, it is particularly pertinent to assess their motivations. In addition, there is sparse evidence regarding this research topic in Portugal. Using a self-administered questionnaire by a sample of university students and adopting multiple logistic regression analysis, the aims of this study are to assess attitudes, knowledge and motivations regarding blood donation and to identify factors associated with donation among young donors.