HIV disease leads to defects in cell-mediated immunity, impairing the immune response to new and recall antigens. We studied 55 HIV 1-infected patients who received of recombinant DNA hepatitis B vaccine and 20 controls. The overall hepatitis B virus (HBV) seroconversion rate was 59%. The median CD4+ T cell count among responders was 452 cell/mm(3), higher than non-responders (359 cells/mm(3)). The HIV plasmaviral loads were higher in non-responders. We concluded that total T CD4 cell count, memory T CD4+ cells and lower plasma viral load among HIV-1-infected subjects treated with HAART could be used to predict the immune response to vaccination with hepatitis B vaccine. Thus, considering cost benefits, HVB vaccination should be preferentially provided to HIV-infected patients with T CD4 cells count over 450 cells/mm(3), preferentially whose under HIV replication controlled.