BACKGROUND: Patient overreliance on short-acting beta2 agonists (SABA), with concomitant underuse of inhaled corticosteroids (ICS), is associated with poor asthma control and increased risk of asthma attacks. OBJECTIVE: To develop and validate a brief questionnaire to elicit patients' perceptions of SABA (eg, belief that asthma is best managed by SABA alone) that could lead them to be overly reliant on SABA. METHODS: The 5-item SABA Reliance Questionnaire (SRQ) was adapted from the well-validated Beliefs about Medicines Questionnaire assessing patient perceptions of the importance of, and necessity for, SABA in managing their asthma. The psychometric properties of the questionnaire were studied using Amazon Mechanical Turk, an online survey platform, in 446 people with self-reported asthma. Internal reliability and criterion-related validity were assessed on the basis of relationships between SRQ scores and other variables, including self-reported adherence to ICSs and perceived importance of reliever inhalers. RESULTS: Internal reliability was good with Cronbach α = 0.74. Criterion-related validity was demonstrated by an inverse correlation between SRQ scores and self-reported adherence to ICSs (r = -0.291; P < .0001), and significant correlation between SRQ scores and perceived reliever importance (r = 0.216; P < .0001), as well as by significant differences in SRQ scores between those with high and those with low self-reported ICS adherence (adherence to ICS t = 4.825; P < .0001). CONCLUSIONS: The SRQ demonstrated acceptable internal reliability, and criterion validity, supporting its potential use as a pragmatic tool for identifying patients whose beliefs are indicative of overreliance on SABA for asthma.