Toll-like receptors (TLRs) play an important role in induction of innate immune responses. The activation of TLRs triggers inflammatory responses that are essential for host defense against invading pathogens. Phenethyl isothiocyanate (PEITC) extracted from cruciferous vegetables has an effect on anti-inflammatory therapy. Dysregulated activation of nuclear factor-${kappa}$B (NF-${kappa}$B), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) has been shown to play important roles in the development of certain inflammatory disease. To evaluate the therapeutic potential of PEITC, NF-${kappa}$B activation and COX-2 and iNOS expression induced by lipopolysaccharide (LPS, TLR4 agonist), polyinosinic-polycytidylic acid (Poly[I:C], TLR3 agonist), 2 kDa macrophageactivating lipopeptide (MALP-2, TLR2 and TLR6 agonist) or oligodeoxynucleotide 1668 (ODN1668, TLR9 agonist) were examined. PEITC inhibits the activation of NF-${kappa}$B induced by LPS or Poly[I:C] but not by MALP-2 or ODN1668. PEITC also suppressed the iNOS expression induced by LPS or Poly[I:C]. However, PEITC did not suppress COX-2 expression induced by LPS, Poly[I:C], MALP-2, or ODN1668. These results suggest that PEITC has the specific mechanism for antiinflammatory responses.