Background: In France, data collected during post-donation follow-up visits indicate that a majority of HIV-infected blood donors should have been deferred because they did not meet the selection criteria. To maintain optimal transfusion safety, it was important to better understand why the screening process had failed to exclude these donors, particularly men who have sex with men (MSM). Materials and Methods: Semi-structured individual interviews were conducted with 32 blood donors who tested HIV-positive between mid-2011 and 2014, with the aim of gathering information on their experience and motivations for donating blood, their understanding of selection criteria, their management of sexual risk, and their opinions on the donor selection process. The interviews were analyzed using an inductive approach. Results: More than 50% (17/32) of the study participants did not meet the blood donor selection criteria. Among the main reasons for not reporting risk factors in the questionnaire or during the pre-donation interview were fear of stigmatization, monitoring of HIV status, symbolic attachment to blood donation, and the context of the donation (confidentiality, type of collection, etc.). Furthermore, the assessment of risky sexual behaviors was not always well understood by the donors themselves. Finally, the concept of the “silent window” and the epidemiological arguments underlying donor selection criteria were poorly understood. The majority of study participants opposed the permanent deferral of MSM. Conclusion: This study demonstrated the need for better communication regarding the silent window and the epidemiological basis underlying blood donor selection criteria to improve donor compliance. These findings have already led to improvements in the pre-donation questionnaire, as part of the 2016 revision of donor selection criteria.