From a synthesis of 59 serosurveys, we estimate and discuss influence of several parameters on feline immunodeficiency virus (FIV) infection. The overall infection rate estimated from 85,529 tested cats is high, 11.04%, besides the virus seems to be rather endemic. Parameters influencing FIV infection are sex, age and roaming habits. Neutering, breed and group size effects seem to be rather indirect. Prevalence differences between countries and potential cofactors are also discussed. Results show that FIV transmission is influenced by behavior. We highlight the important bias of this kind of surveys and propose to sample rather natural populations of cats, taking into account their dynamical and ecological parameters. This synthesis highlights arguments in accordance with the hypothesis that FIV is not a recent virus.