Accidental blood exposure incidents require immediate medical evaluation, allowing for early treatment for possible infection, if needed, and enabling the identification of an occupational accident in the case of HIV infection. A study was conducted with nursing students in two different years of study in order to ascertain the rate of underreporting of blood exposure incidents and to determine the reasons for it. The results highlight that, over a period of three years of training, 52% of blood exposure incidents were not declared as occupational accidents. The reasons that nursing students underreport blood exposure incidents are related to the negative perceptions and feelings that students have (personal fault 55% and awkwardness 82%), and to the fear of its negative consequences (31%) on the evaluation of their internship in particular and on their nursing training in general. On the other hand, students copy the behavior of other caregivers who themselves underestimate the risk of blood exposure incidents (22%). The identification of these elements will help to initiate a discussion and to prepare direct actions in order to encourage reporting of blood exposure incidents by nursing students and their colleagues during internships.