Increased production of reactive oxygen species leading to an imbalance between the oxidative forces and the antioxidant defense systems favoring an oxidative injury has been implicated in the pathogenesis of asthma. The aim of the study was to investigate the peripheral DNA damage, and its association with oxidative and antioxidative measurements in children with asthma bronchiale. The study population contained 42 children with asthma bronchiale and 32 healthy controls. DNA damage was assessed by alkaline comet assay in peripheral lymphocytes. Plasma levels of total antioxidant status (TAS), total peroxide concentration (LOOHs), and total oxidant status (TOS) were determined. In asthma bronchiale patients, DNA damage was significantly higher than in controls (17.9 +/- 11.8 AU vs. 1.2 +/- 2.0 AU, p < 0.001). Plasma TOS and LOOHs were higher in patients than in healthy controls (13.4 +/- 7.0 vs. 9.0 +/- 3.5, p = 0.002; 9.9 +/- 3.4 vs. 4.4 +/- 1.5, p < 0.001, respectively). Plasma TAS level in patients was higher than in healthy controls (5.5 +/- 2.5 vs. 1.0 +/- 0.6, p < 0.001). DNA damage was correlated with TOS (r = 0,616, p < 0.001). The findings indicated that lymphocyte DNA damage level increases in children with asthma bronchiale. Elevated DNA damage may be related to increased oxidative stress. However, the mechanism of this association, and whether it is direct or indirect, remains to be explored.