OBJECTIVES: Non-adherence to asthma medication can lead to lower disease control and asthma exacerbations that may be fatal. This survey assessed the attitude and expectations of Belgian asthma patients towards their treatment. METHODS: This cross-sectional survey was conducted between June 2015 and February 2016 in 70 Belgian pharmacies. Participants completing the survey had to be ≥15 years, diagnosed with asthma, and on inhaled corticosteroid-based treatment. The analysis included 80 completed questionnaires. RESULTS: Participants comprehended well that controller drugs are intended to prevent the occurrence of asthma symptoms and complications, and their long-term daily use should be maintained. Twenty seven percent of participants indicated fear of side effects concerning long-term daily use of a controller inhaler. Participants had a good understanding that quick-relief drugs are intended to (quickly) relieve asthma symptoms and do not need to be used on a systematic, daily basis. Out of 73 participants on long-term controller drugs, 33 (45%) were 'non-adherent' (used less frequently than prescribed). Suboptimal adherence to maintenance treatment appeared to increase nightly awakenings and the risk of restrictions in activities due to asthma. Out of 54 participants with available quick-relief drug adherence data, 18 (33%) were non-adherent (used their quick-relief drug more frequently than prescribed). DISCUSSION: This survey confirms suboptimal adherence to maintenance controller therapy and overuse of short-acting reliever medications among Belgian patients, which affects asthma control and quality of life. A substantial proportion of patients expressed fear about their chronic therapy, indicating the need for patient education about their disease and its management.