Asthma is a disorder characterized by inflammation of the airways. Oxidative stress may play a role in the pathophysiology of several diseases including asthma. Characterizing biomarkers of oxidative stress in the context of other systemic measures of immune function or inflammation could provide insight regarding underlying mechanisms inducing asthma. We evaluated whether oxidative stress in the form of plasma reactive oxidants differs between asthmatic and non-asthmatic children and elucidate relationships between plasma reactive oxidants and other asthma-related immunological markers. Plasma reactive oxidants, white blood cell counts, total serum immunoglobulin E(IgE), and a multi-allergen-specific IgE screen were measured in 74 asthmatic and 74 non-asthmatic children(9 to 13 years of age) from the Detroit, Michigan area. Plasma reactive oxidants were measured using a lucigenin-based chemiluminescence assay. Plasma reactive oxidants, eosinophils, and neutrophils(absolute counts and percent of total white blood cell counts), total IgE, and allergen-specific IgE levels were elevated in asthmatics after adjusting for age, gender, and ethnicity. IgE(total or allergen-specific), eosinophils and neutrophils were not significantly associated with plasma reactive oxidant levels. The association between plasma reactive oxidants and asthma status was similar when eosinophils, neutrophils, total IgE, or allergen-specific IgE were included as possible confounders in multivariate logistic regression models. In conclusion, plasma reactive oxidants are elevated in asthmatics and appear to be an independent predictor of asthma status. Measurement of plasma reactive oxidants may be a useful adjunct diagnostic tool and potential mechanistic indicator relevant to the study of asthma and asthma exacerbation.