One of these novel application areas is LLLT for drug-induced liver injury. LLLI employs visible (generally red) or near-infrared light generated from a laser or light-emitting diode (LED) system. The light is typical of narrow spectral width between 600-1000 nm. Despite significant research efforts around the effects and molecular mechanisms of LLLT in various cells or tissues, the appropriate doses of radiation, energy densities, time, and irradiation conditions as well as the appropriate individual settings in the various laser devices, which will predictably lead to optimal therapeutic effects, have not been clarified yet. In the present study, the effect of low-level laser irradiation on oxidative stress parameters in rats under the conditions of BPA administration was investigated. Toxic liver injury induced by bisphenol A (BPA) administration at 50 mg/kg body wt by gavage for 3 days once a day. Low-level laser irradiation was performed after each administration of xenobiotic. A laser diode (50 mW) with 650 nm continuous wavelength was applied to the skin surface at the anatomical site of the liver. The administration of BPA leads to the evaluated of free radical generation and decrease in SOD, CAT and GPx activities in the liver of bisphenol A-exposed animals. The enhanced processes of the generation of superoxide radicals and nitric oxide and exhausting level of antioxidant enzymes under the conditions of BPA administration leads to the increased oxidative damage of lipid and protein in subcellular fraction. The low-level laser irradiation of BPA-treated animals leads to the increase of enzymatic activity of antioxidant defences system, a decrease of free-radical production and oxidative protein and lipid damage in microsome and cytosol.