Introduction - The national epidemiological surveillance of blood donors aims to monitor the prevalence and incidence of bloodborne infections (HIV, HTLV, HCV, and HBV), identify risk factors, and assess the residual risk of transmitting these infections through transfusion. It also contributes to the evaluation of donor selection. This article presents data from the 2003–2005 period. Methods - Prevalence rates were calculated among new donors, and incidence rates among known donors who donated at least twice during the 2003–2005 period. Residual risk was estimated using the "incidence rate/window period" model. Results - Over the 2003–2005 period, the prevalence rate of HBsAg (11.1 per 100 new donors) was 1.7 times higher than that of HCV (6.6 per 100), 10 times higher than that of HTLV (1.1 per 100), and 23 times higher than that of HIV (0.5 per 100). Conversely, HIV had the highest incidence (1.16 per 105 person-years), a rate twice as high as that for HCV (0.56 per 105), 2.5 times higher than for HBV (0.47 per 105), and 14 times higher than for HTLV (0.09 per 105). The residual risk of transmitting these infections through transfusion was estimated for the 2003–2005 period at 1 in 1,700,000 donations for HBV, 1 in 2,600,000 for HIV, 1 in 6,500,000 for HCV, and 1 in 8,000,000 for HTLV. Conclusion - Thanks to continuous improvements in donor screening, advances in the biological testing of donations, and preventive measures taken in the general population to prevent these infections, the risk of transmission of HIV, HTLV, HCV, and HBV through transfusion is now very low. (R.A.)