To investigate the impact of adaptive oxidative training with inhaled gaseous superoxide (GS) on endogenous oxidative stress (EOS) and lung function in asthmatics and healthy volunteers, short-term GS inhalation was repeated. The study involved 27 patients (median age 42 (34 to 44) years with atopic bronchial asthma and a median disease duration of 130 (120 to 180) months prior to the investigation and 8 healthy volunteers whose median age was 20.5 (18 to 25 years). The rates of GS generation at a distance of 1 cm from the source was 0.25 mumol/min. The examinees inhaled GS nasally over 15 minutes per session, on an average of 20 times over 2 periods of 4 weeks each. Spirometric studies, a mathacholine challenge test, salbutamol test and blood cell count were performed, and blood antioxidative components were measured. There is evidence that GS inhalations in asthmatics cause an adaptive oxidative training and promote reductions in EOS, as well as activation of antiinflammatory mechanisms and improved spirometric parameters.