In traditional medicine, there are many natural crude drugs that have the potential to treat many diseases and disorders and one of them is Thymus. Thymus is a genus to the family Lamiaceae. Antibacterial activity of Thymus is related to thymol. The purpose of this investigation is to evaluate the susceptibility of L. monocytogenes strains isolated from red meat to antibacterial activity of Thymus trautvefferi . Penicillin was used as positive control.