The authors presented characteristic features of mild persistent asthma, the method of diagnosing and optimal treatment of this disease. The Global Initiative for Asthma (GINA) quidelines describe mild, persistent asthma as having asthma symptoms more than weekly, but less than daily, nocturnal symptoms more than twice monthly, but less than weekly, with normal lung function (FEV₁ or PEF‡80%) between asthma episodes. Patients suffering from mild, persistent asthma constitute a major portion of asthmatics. They rarely attend their physician because of symptoms of asthma, although sometimes they experience very severe attacks of dyspnoea. Some studies revealed that it is difficult to diagnose mild asthma because ventilatory parameters are normal, and bronchial reversibility test is negative. Studies based on examination of induced sputum and bronchial biopsies proved that markers of inflammation and airway remodeling airway are related to severity of disease. In mild asthma these consequences of long-term inflammation are very often as in moderate asthma. Most large studies which have studied the influence of inhaled corticosteroids waron mild asthma, revealed that this therapy is very effective. The first published was the OPTIMA trial. In this study two groups of asthmatic were selected to evaluate the efficacy of budesonide alone compared with combination budesonide and formoterol for 1 year. The rate of severe asthma exacerbationis per patient per year, and days with any asthma symptoms, poorly controlled asthma days and night with nocturnal symptoms were markedly reduced. The second study evaluating inhaled corticosteroids was START trial, which examined the effects of early intervention with budesonide in new-onset persistent mild asthma. Severe asthma exacerbations which required an emergency room visits or hospitalization in budesonide group were significantly reduced. The mast recently published study reported that it may be possible for patients with mild persistent asthma to be treated with intermittent courses of inhaled or oral corticosteroids. This conclusion was given despite the fact that the regular use of inhaled budesonide was better than intermittent.