Objectives To evaluate asthma characteristics and treatment patterns, including short-acting β2-agonist (SABA) prescriptions, in primary and specialist care in the Singapore cohort of the SABA use IN Asthma (SABINA III) study.Design Cross-sectional, observational study.Setting Multicentre study conducted at five sites across Singapore.Methods In patients with asthma (aged ≥12 years), data on demographics, disease characteristics and asthma treatment prescriptions were collected using electronic case report forms. Patients were classified by investigator-defined asthma severity (guided by 2017 Global Initiative for Asthma recommendations) and practice type (primary/specialist care).Results Of the 205 patients analysed (mean (SD) age, 53.6 (16.8) years; female, 62%), 55.9% were enrolled by specialists and 44.1% by primary care physicians. Most study patients (80.5%) had moderate-to-severe asthma (86.0% in specialist care and 74.4% in primary care). In the 12 months before study enrolment, 18.0% of patients experienced ≥1 severe exacerbation. Asthma was well or partly controlled in 78.0% of patients. Overall, 17.1% of all patients were overprescribed SABA (≥3 SABA canisters/year) in the preceding 12 months, and overprescription was greater in specialist versus primary care (26.3% vs 5.6%). Only 2.9% of patients were prescribed SABA monotherapy, while 41.0% received SABA in addition to maintenance therapy. Among the latter, 40.5% were overprescribed SABA. Overall, a higher percentage of patients prescribed ≥3 SABA canisters (vs 0–2 SABA canisters) were assessed as having uncontrolled asthma during the study visit (42.9% vs 17.6%). Maintenance therapy in the form of inhaled corticosteroids (ICS) or ICS/long-acting β2 agonist fixed-dose combinations were prescribed to 14.1% and 84.9% of patients, respectively, in the 12 months before enrolment.Conclusions In this Singapore cohort, ~17% of all patients and more than 40% of patients prescribed SABA in addition to maintenance therapy were overprescribed SABA. These ...