Objectives: Adherence to therapy is very important and many factors could be responsible for this issue. Suboptimal adherence to asthma therapy is a major contributor to poor asthma outcomes. Our aim is to find out the most important factor responsible for adherence to therapy in bronchial asthma patients.Subjects and methods: The study included 143 patients with persistent bronchial asthma. Factors that may affect adherence to therapy were studied. These factors included age, sex, residence, level of education, proper asthma education and whether inhaled corticosteroid (ICS) was taken alone, with long acting b2 agonist (LABA) in separate devices or with LABA in a combined form. Adherence to ICS was determined according to Medication Rating Scale.Results: We found that 55.3% of patients that received asthma education were adherent to ICS while only 21% of patients that did not receive asthma education were adherent to ICS therapy. The difference was statistically highly significant (p = 0.003). Other factors do not significantly affect adherence to ICS. Patients that used combined ICS with LABA in the same device were significantly more adherent to therapy (60.25%) than patients that used the same combination in 2 separate devices (34.5%). All patients with well controlled asthma were adherent to ICS, while 47.5% of uncontrolled patients was adherent. Comparison between level of control and adherence to ICS was highly significant (p = 0.003).Conclusion: This study showed how different factors may modulate adherence to asthma treatment and confirmed the importance of patient education in increasing adherence to asthma therapy.