Using comet assay we studied the effect of anxiolytic afobazole, exhibiting also antioxidant and antimutagenic properties, on spontaneous and ex-vivo hydrogen peroxide-induced DNA damage in blood cells from patients with systemic lupus erythematosus. Afobazole treatment (30-60 mg/day for 1 month) in addition to standard therapy decreased spontaneous level of DNA damage in blood cells. The level of ex vivo hydrogen peroxide-induced DNA damage decreased by 49% in this group of patients. The number of cells hypersensitive to hydrogen peroxide yielding DNA comets with highly damaged DNA also decreased by 51%. No significant changes in the analyzed parameters were found in the placebo group. Addition of afobazole to complex therapy of patients with systemic lupus erythematosus reduced the level of DNA damage in blood cells and improved cell resistance to oxidative genotoxic exposure.