Oxidative stress has been implicated in many chronic diseases and the use of natural antioxidants has been suggested to be beneficial in the prevention and management of some chronic diseases. Deep Root^® herbal mixture (DRHM) is a branded Nigerian polyherbal drug composed of Cymbopogon citratus (17%), Carica papaya leaves (16%), Magnifera indica bark (15%), Moringa oleifera leaves (14%), Citrus limonia (12%), Psidium guajava (11%), Zingiber officinale root (9%) and Allium sativium (6%). Considering the bioactivities of the individual plant components in literature and the indications for managing chronic diseases, the potential of modulating hydrogen peroxide (H₂O₂)-induced oxidative stress in rats by DRHM was assessed. Thirty healthy male Wistar rats used for this study were divided into six groups of five rats each with group 1 serving as normal control - was neither intoxicated nor treated with any drug. Groups 2-6 were intoxicated (3 ml/kg b.w of 5% v/v of H₂O_2, i.p). Group 2 served as H₂O₂ control, groups 3-5 received 1, 2 and 3 ml/kg/d b.w. p.o of DRHM, respectively while group 6 was given silymarin (100 mg/kg/d. b.w. p.o) for 14 days. The hematological, liver, lipid peroxidation and antioxidant status of H₂O₂-intoxicated rats were evaluated. H₂O₂ elevated aspartate and alanine aminotransferases activities, and malondialdehyde and total bilirubin levels (p < 0.05). Conversely, H₂O₂ decreased superoxide dismutase, catalase and glutathione peroxidase activities, and antioxidant vitamins and reduced glutathione levels, hemoglobin concentration, packed cell volume, red blood cell, white blood cell and platelet counts (p < 0.05). However, in a dose-dependent manner, DRHM reversed the hematological status and attenuated oxidative damage to hepatic tissues likely by enhancing antioxidant defense system. This effect may be attributed to the phytoconstituents detected in DRHM. The polyherbal drug was shown to be tolerable up to 10 ml/kg. b.w. dose.