The study of the HIV co-receptors has important implications for understanding viral tropism and pathogenesis. In this context, haemophiliacs represent an interesting cohort of individuals, as they were at continuous risk of being infected by transfusion. Therefore, we studied polymorphisms in chemokine receptor genes (CCR5, CCR5 promoter, CCR2) and in the chemokine ligand (SDF-1) for CXCR4, in blood donors and patients, to evaluate their effect on the virus infectivity. In blood donors we found that the allelic frequencies for the polymorphisms are similar to the values found in the haemophiliacs, with no distinction between HIV-I and/or HIV-2 positive and negative groups. In conclusion, our data does not support an essential role for these mutations to protect against HIV-1 and/or HIV-2 infection through parenteral transmission (in conditions where neither the value of the inoculum nor the number of inoculations are specified).