HLA-G antigens are non classical HLA-class I anti-inflammatory molecules. Since styrene exposure has been suggested to induce immune alteration, we analyzed plasma levels and “in vitro” peripheral blood mononuclear cell (PBMC) production of soluble HLA-G (sHLA-G) and Interleukin-10 (IL-10) molecules after lypopolysaccharide (LPS) stimulation, in styrene exposed workers and healthy subjects. Exposed workers showed reduced plasmatic levels of sHLA-G and IL-10 in comparison to healthy controls. Similarly, lower levels of sHLA-G and IL-10 molecules were observed in PBMC culture supernatants after LPS activation. These data propose styrene exposition as a mediator of an impaired sHLA-G production.