The debate about the presence of HIV-1 particles in human gametes and recent experimental results are reported in detail. Using immunocytochemistry, in situ hybridization at electron microscopy level, polymerase chain reaction and in vitro fertilization, it has been demonstrated that human spermatozoa can incorporate HIV-1 using special receptors, different from the usual CD4, and that they remain active and able to vehicle the viral particles into the oocyte, which is regularly fertilized. Moreover, by transmission electron microscopy (TEM), immunocytochemistry and PCR, we demonstrated that cell-free HIV-1 is not able to bind and penetrate the human oocyte in vitro. We attribute this behaviour to the fact that the oocyte and cumulus cells are devoid both of GalAAG and of CD4 receptors. PCR analysis indicated that mRNAs specific for CD4, CXCR4 and CCR5 proteins were absent, too.