Egg has ben documented as a rich source for the supply of biologically active peptides. This study characterizes the immunomodulatory effects of an egg white enzymatic hydrolysate (EWH) using a BALB/c mouse model of egg allergy. Mice were orally sensitized to egg white and subsequently gavaged with EWH. ELISA results indicated significant reductions of both serum histamine and specific IgE titers in EWH-fed mice, accompanied by a repression of both IL-4 and IFN-gamma production in spleen cell cultures. Similarly, real-time RT-PCR analyses highlighted decreased mRNA expression of IFN-gamma and IL-12 (Th1-biased), as well as lower ratios of IL-4 and IL-13 mRNA (Th2-biased). On the other hand, increased intestinal expressions of TGF-beta and FOXp3 mRNA were determined in EWH-fed mice, suggesting induction of local regulatory mechanisms. The presence of immunodominant epitopes was proposed to be responsible for the immunomodulatory effects observed.