Genetic research involving biobanks has been the subject of numerous declarations, recommendations and guidelines produced by professionals, administrators, legislators and other decision-makers. Yet, there is little published empirical information on people's willingness to participate in genetic studies on blood samples that they donated many years ago, at a time when the informed consent did not include the possibility of genetic research. We here report on our experiences of obtaining informed consent for academic and as well as commercial genetic research on blood samples collected more than a decade ago. Participants in a population-based risk factor survey who had donated blood to a biobank in 1990 were contacted eleven years later (in 2001) and asked for informed consent for genetic studies. A total of 1,311 out of 1,409 participants (93%) gave their consent to use blood samples for academic genetic research, provided that an Ethics Committee had approved the research. Thirty-one participants (2.2%) did not give their consent for academic genetic research. Another 35 subjects (2.5%) did not consent to industrial genetic research even if their blood samples were anonymized. Sixty-four individuals did not reply or provided incomplete answers (together 4.8%). Of the 1,311 individuals that agreed to participate, 292 (22.3%) wanted to be informed and give their concent to every new specific project. All the others gave a general concent provided that an Ethics Committee had approved the research.