Inhaled corticosteroids (ICS) are the mainstay of asthma treatment, preventing asthma symptoms, exacerbations and hospitalisations. Despite the effectiveness of current asthma treatments, non-adherence to inhaled corticosteroids remains a significant problem. An analysis of the patients’ beliefs about medicines is of great importance due to its association with the patients’ adherence . Validated questionnaires are used for this purpose, and one of them is Beliefs about Medicines Questionnaire (BMQ). The aim of this study was to evaluate patients’ adherence and beliefs about their inhaled corticosteroids therapy and drugs in general using the BMQ and MMAS-4 questionnaires as well as explore the association of patients’ beliefs and adherence. Additionally, we explored patients’ understanding of the inhaled corticosteroid therapy focusing on the indication, safety and effectiveness. 97 asthma patients (69,1% women, median age being 37 years (18-84)) on inhaled corticosteroids therapy, participated in the study. The results have shown that patients are mostly not concerned about taking inhaled corticosteroids and generally believe in the positive effects and the benefits of the medications themselves. The analysis of the MMAS4 questionnaire, demonstrated non-adherence as an important issue (MMAS-4 score was...). There was a higher adherence in older patients compared to younger patients. The students had weaker beliefs about the necessity of inhaled corticosteroids, and this could be one of the reasons for their lower adherence. Moreover, patients with higher level of education were more adherent. A qualitative part of the questionnaire showed that most patients have very good understanding of why they take an inhaled corticosteroid (indication). Furthermore, most respondents (89.7%) consider inhaled corticosteroids to be effective. 10.3% experienced a side effect of inhaled corticosteroids. The BMQ questionnaire has not been used in the population of asthmatic patients on inhaled corticosteroids therapy in Croatia so far, and this research obtained first results for better understanding of patients’ beliefs and their understanding of the therapy as well as the adherence. The results of this study could contribute in developing the strategies for increasing adherence and consequently better therapy outcomes