Plasma oxidative stress parameters such as as total oxidant status (TOS) and total antioxidant status (TAS) were well studied in some chronic allergies, but their role is not well known in acute allergic disease such as acute urticaria (AU). The aim of this study is to investigate the oxidative and antioxidative status in children with AU. Eighty-seven children with noninfectious AU and 70 healthy controls were enrolled in the study. Blood samples were taken for complete blood count, serum immunoglobulin E (IgE), and C-reactive protein (CRP) levels routinely and for TOS and TAS. The skin prick test was performed and/or specific IgE assays were performed as indicated. Blood samples were also taken for TAS and TOS in the control group. Forty-eight (55%) of the children with AU were male, 39 (45%) of them were female. Mean ages were 6 +/- 2.02 and 7 +/- 1.38 years in the study and control groups, respectively. TOS levels were significantly high and TAS levels were significantly lower in the acute urticarial group (P < 0.001) than controls. There was no significant correlation between age, total IgE levels, or eosinophil count and TAS and TOS levels in children with AU. Plasma TOS levels are elevated in children with AU. The high level of TOS indicates that children with AU were exposed to severe oxidative stress.