Background: The impact of presumed consent on donation rates has been widely debated. In June 2013 Greece adopted a 'soft' presumed consent law for organ and tissue donation, where relatives' approval is sought prior to organ removal. Aims: To report on the knowledge, attitudes and concerns of undergraduate students, enrolled in three health science disciplines, in regards to organ donation and presumed consent. Methods: Undergraduate junior and senior health science students [medical (MS), nursing (NS) and medical laboratory students (MLS)] were recruited from higher education settings in Thessaly, Greece. Dichotomous questions, previously used, were adopted to assess knowledge, attitudes and concerns towards organ donation, together with questions regarding the recent presumed consent legislation. Results: Three hundred seventy-one out of 510 students participated in the study (response rate: 72.7%). Only 3.6% of NS, 8.7% of MS and 3.2% of MLS carried a donor card. Although over 78% in all groups knew that it was possible to leave kidneys for transplant after death, only 10% to 39% considered themselves well-informed. NS were more likely to consider opting-out (21.5%), followed by MLS (17.9%) and MS (10.9%). Respondents were more likely to refuse organ removal upon death when expressing one of the following views: a) opposing a system making it lawful to take kidneys from an adult who has just died, unless forbidden while alive [Odds ratio (OR) 95% Confidence Interval (CI): 2.96 (1.48-5.93), p=0.002], b) worrying about their kidneys being removed after death [OR, 95% CI: 3.37 (1.75-6.49), p=<0.001] and c) believing that an intact body was needed after death [OR, 95% CI: 4.23 (2.15-8.31), p<0.001]. Conclusion: Health science students, soon to become healthcare professionals, demonstrated limited awareness in regards to the newly reformed organ donation system. Identified knowledge deficits and concerns could have far-reaching implications in terms of conveying a clear message and shaping the public's stand. The feasibility and effectiveness of a joint inter-professional curriculum on organ and tissue donation issues across all three health science disciplines, addressing common themes and concerns deserves further study.