Background: Results of previous research indicate that adherence to prescribed inhaled corticosteroid-long-acting beta2-agonist (ICS-LABA) asthma controller medications is suboptimal, yet actual daily-use patterns are unclear and may be influenced by regimen complexity or dosing frequency. Objective: To investigate real-world use of asthma medications by using inhaler sensors for the ICS-LABA controllers: twice-daily fluticasone propionate (FP) plus salmeterol (SAL) and once-daily fluticasone furoate (FF) plus vilanterol (VI); and albuterol rescue medication. Methods: This longitudinal, two-phase, observational study included adults with asthma-prescribed FP-SAL (phase I) or FF-VI (phase II), and albuterol metered-dose inhalers. The participants completed baseline and follow-up surveys, and used clip-on inhaler sensors to monitor real-time inhaler use over the 6-month study period. Pharmacy claims data for the 6-month follow-up period were used to assess refills of ICS-LABA and albuterol inhalers. Results: Patients who used twice-daily FP-SAL received a sufficient dose (≥2 actuations/day) approximately one third of the time, those on once-daily FF-VI received a sufficient dose (≥1 actuation/day) ∼60% of the time. Patients who used once-daily FF-VI were more likely to take their medication as prescribed versus those who used twice-daily FP-SAL. There were no significant differences in the percentage of albuterol-free days (FP-SAL, 68.06% [n = 241]; FF-VI, 72.67% [n = 127]; p = 0.230). Exploratory outcomes are reported in this article's Online Supplemental Material. Claims-based measures of adherence were higher than sensor-based measures, hence claims data may have overestimated adherence, whereas sensors may have more accurately measured patients' medication use. Conclusion: These data supported the use of inhaler sensors as tools to directly and accurately measure ICS-LABA adherence and rescue medication use, and the adherence benefits of once-daily versus twice-daily ICS-LABA regimens.