We have assessed metabolic and immunological effects of a nelfinavir-containing regimen in healthy HIV-1-uninfected individuals receiving post-exposure prophylaxis. Our data suggest that this regimen is well tolerated and did not modify the lipid or hepatic profiles. This antiretroviral regimen seems to have no effect on lymphocyte T cell subsets, however, it could have an immune-modulator role, inducing an increase in the proliferative responses to mitogens.