An as-needed combination preventer and reliever regimen was recently introduced as an alternative to conventional daily preventer treatment for mild asthma. In a subgroup analysis of the PRACTICAL study, a pragmatic randomised controlled trial of budesonide-formoterol reliever therapy versus maintenance budesonide plus terbutaline reliever therapy in adults with mild asthma, we recently reported that about two-thirds preferred as-needed combination preventer and reliever therapy. The aim of this study was to determine the relative importance of attributes associated with these two asthma therapies in this subgroup of participants who indicated their preferred treatment in the PRACTICAL study.At their final study visit, a subgroup of participants indicated their preferred treatment and completed a discrete choice experiment using the Potentially All Pairwise RanKings of all possible Alternatives method and 1000minds software. Treatment attributes and their levels were selected from measurable study outcomes, and included: treatment regimen, shortness of breath, steroid dose and likelihood of asthma flare-up.The final analysis dataset included 288 participants, 64% of whom preferred as-needed combination preventer and reliever. Of the attributes, no shortness of breath and lowest risk of asthma flare-up were ranked highest and second highest, respectively. However, the relative importance of the other two attributes varied by preferred therapy: treatment regimen was ranked higher by participants who preferred as-needed treatment than by participants who preferred maintenance treatment.Knowledge of patient preferences for treatment attributes together with regimen characteristics can be used in shared decision-making regarding choice of treatment for patients with mild-moderate asthma.ACTRN12616000377437.