Regarding the role of free radicals in pathogenesis of inflammatory bowel disease (IBD), we were interested to investigate the effects of Teucrium persicum with approved antioxidant and anti-inflammatory properties in an experimental model of colitis. Immunologic colitis was induced by rectal administration of a mixture of 2,4,6-trinitrobenzene sulphonic acid (TNBS) and ethanol through rubber cannula into rats. Three different doses of Teucrium (100, 200, and 400 mg/kg) were gavaged in a duration of 10 days to rats. Endpoint markers of colitis included macroscopic and microscopic examination of colon tissue and measuring colonic cells concentrations of tumor necrosis factor-alpha (TNF-alpha), interlukin-1beta (IL-1beta), total antioxidant power as ferric reducing antioxidant power (FRAP), myeloperoxidase (MPO), and lipid peroxidation as thiobarbitoric acid-reactive substance (TBARS). Teucrium at all doses improved both macroscopic and histological damages of rats with colitis. Teucrium reduced colonic MPO activity and concentrations of cellular lipid peroxides, TNF-alpha, and IL-1beta, with a concomitant increase in FRAP value in rats with colitis. It is concluded that beneficial effects of Teucrium in experimental colitis is mediated through its antioxidant and anti-inflammatory potentials. Examination of this herbal medicine in patients with IBD as a supplement would further reveal the potential of Teucrium.