RATIONALE: The benefit of budesonide/formoterol maintenance and reliever therapy (BUD/FM MRT) is well documented in GINA Step 3–5 asthma patients. However, its role and efficacy in milder asthma patients needs further investigation. METHODS: A post-hoc analysis of three studies focused on patients with milder asthma, i.e. those previously treated with low-dose ICS (≤400 µg BUD equivalent [eq]/day) with baseline post-bronchodilator (BD) FEV 1 ≥80% predicted, comparing patients randomised to BUD/FM MRT or higher-dose BUD (HD-BUD) plus SABA as needed. Efficacy was assessed by exacerbation rate, FEV 1 and reliever use for all patients, and according to baseline reliever use (terbutaline Turbuhaler® 0.5 mg): <1, 1–2, >2 inh/day (Strata 1–3, respectively). RESULTS: 889 patients (age 36.5 years; men 36.3%; post-BD FEV 1 94.3% predicted; BUD eq 357 µg/day; reliever use 0.59, 1.49, 3.24 inh/day [Strata 1–3]) were included in the analysis. Baseline data were similar for Strata 1–3. In the whole cohort, BUD/FM MRT significantly increased FEV 1 (110 mL) and reduced exacerbation rate (RR 0.62) and reliever use (–0.47 inh/day) vs HD-BUD (p all <0.002). For Strata 1–3, respectively, BUD/FM MRT vs HD-BUD reduced exacerbation rate (RR 0.61, 0.69, 0.64; p=0.08–0.12) and increased FEV 1 (100, 90, 130 mL; p all <0.02). Reliever use was significantly lower with BUD/FM MRT in Strata 2 (–0.29) and 3 (–0.78) but not in Stratum 1 (+0.11 inh/day). CONCLUSIONS: In a milder asthma cohort, BUD/FM MRT improved exacerbations, lung function and reliever use more than HD-BUD plus SABA. The treatment differences were similar for lung function and exacerbations across the range of baseline reliever use, including <1 inh/day. FUNDING: AstraZeneca.