An effect of beclomethasone dipropionate (Beclocort-Polfa) was investigated in the group of 24 patients with atopic and non-atopic bronchial asthma who have shown unspecific bronchial hyperreactivity to histamine during the periods of remission. The drug was administered in the form of aerosol in a daily dose of 1.0 mg for 4 weeks. Provocative histamine dose was established with Bronchoscreen device (Jaeger) thrice:prior to the treatment, after 1 week of placebo therapy, and after 1 month of beclomethasone administration. Statistically significant increase in histamine dose for provocation of bronchospasm (p < 0.01) being nearly twice higher than the baseline value has been noted in patients treated with beclomethasone dipropionate aerosol. It advocates such a treatment in unspecific bronchial hyperreactivity independently of the type of the bronchial asthma.