Seabuckthorn (Hippophae rhamnoides L.) berry has a long history of applications as a food and medicinal ingredient in eastern countries. The present study was carried out to investigate the effect of different fruit extracts of H. rhamnoides on altered biochemical parameters indicative of haematological alterations, tissue oxidative stress, and arsenic concentration in arsenic-exposed mice (2.5 mg/kg body weight, intraperitoneally). Two aqueous extracts (at room temperature and under reflux condition) and an ethanolic extract of H. rhamnoides at a dose of 500 mg/kg body weight were co-administered daily during arsenic exposure in mice for 3 weeks. Exposure to arsenic led to a significant inhibition of blood delta-aminolevulinic acid dehydratase (ALAD) activity, suggesting disturbed haem synthesis pathway. Arsenic also caused significant depletion of reduced hepatic glutathione (GSH) level, glutathione S-transferase (GST) and glutathione peroxidase and catalase activities, while it increased the level of thiobarbituric acid reactive substance (TBARS), suggesting liver oxidative stress. Most of the altered biochemical variables responded favorably to the co-supplementation of H. rhamnoides, particularly the aqueous fruit extract, extracted at room temperature (HF-WRT). However, arsenic concentration in blood and tissues remained unchanged, suggesting the lack of chelating property of fruit extract of H. rhamnoides. The present study, thus, led us to conclude that the fruit extract of H. rhamnoides has a significant protective role against arsenic-induced oxidative injury. However, it lacks the ability to remove arsenic from the binding sites, suggesting that the herbal extract could be co-administered with a chelating agent of known efficacy during treatment of arsenic to achieve the optimum effect of chelation treatment.