OBJECTIVES Increased health care resource utilisation (HCRU) is associated with inadequately controlled asthma. Here, we evaluate the impact of omalizumab on HCRU in patients with moderate or severe persistent asthma. METHODS A retrospective case-crossover study was conducted using the Truven MarketScan database. Data between 1-January-2007 to 30-September-2012 was collected for analysis. Patients included in the analysis had to have a diagnosis of moderate or severe persistent asthma, be ≥12 years of age during the analysis period, have had 2 years of continuous enrolment (1 year pre/post omalizumab index date), and have had exposure to omalizumab continuously for ≥12 months. All-cause and asthma-related HCRU during the years, pre and post omalizumab initiation, were compared using McNemar tests and 2-sided paired Student’s t test. Data were stratified by asthma severity based on NHLBI criteria. RESULTS A total of 429 patients (mean age, 46.6 years; female, 59.0%; Moderate=340 [79.3%], Severe=89 [20.7%]) from the database were included in the analysis. The use of omalizumab was associated with 49.3% (p=0.0003), 54.0% (p=0.001), and 35.3% (p=0.1466) reductions in the mean number of asthma-related ER visits and 69.2% (p=0.0005), 65.5% (p=0.0045), and 80.0% (p=0.0449) reduction in the mean number of asthma-related hospitalisations among All, Moderate, and Severe asthma patients, respectively. The mean length of stay for asthma-related hospitalisations was also reduced to 71.2% (p=0.0002), 64.5% (p=0.0016), and 90.6% (p=0.0442) in All, Moderate, and Severe patients respectively. All-cause ER visits were reduced by 30.8% (p=0.0014), 32.5% (p=0.0045), and 25.0% (p=0.1348), and hospitalisation reduced by 48.9%, 45.2%, and 64.7% (all p≤0.0155) in All, Moderate, and Severe asthma patients respectively. Cohort analysis of severe asthmatics was limited by sample size. CONCLUSIONS In patients with moderate persistent asthma, omalizumab use was associated with significant reductions in all-cause and asthma-related HCRU.