This study measured the antioxidative and nutrient responses of the common reed (Phragmites aus-tralis (cav.) Trin. Ex Steudel) to arsenic at different sampling sites in the contaminated Chelpo area in Khorasan Province, northeast Iran. In order to model a successful phytoremediation strategy for the polluted area, we collected common reeds from five sampling sites in the Chelpo arsenic-polluted area, and compared them with samples collected from an unpolluted area. Arsenic, calcium, manga-nese, iron, magnesium and zinc were measured in different parts (root, rhizome, stem and leaf) of the common reed, using a graphite furnace atomic absorption spectrometer. Arsenic uptake by the common reed enhanced shoot uptake of nutrient elements such as calcium, manganese, iron and potassium, with the exception of magnesium, zinc, phosphorus and sodium, whose concentrations mostly decreased. Maximum root uptake of iron and potassium was approximately 3.5 and 2.5 times that of the control plants, respectively. Hydrogen peroxide (H2O2) content; enzymatic antioxidants (catalase, ascorbate peroxidase and guaiacol peroxidase); and total carotenoids increased signifi-cantly with increased arsenic uptake. However, the increment of total chlorophyll did not differ signif-icantly between sampling sites. Although the results indicated that enzymatic antioxidants and nutrient changes played significant roles in arsenic detoxification, we suggest that the common reed can be applied as an arsenic-tolerant species in arsenic remediation at Chelpo and similar contami-nated sites throughout the world.