The aim of a new study published in Medicine was to explore the efficacy of tiotropium in treating patients with moderate-to-severe asthma on the basis of qualified randomized controlled trials (RCTs).This was a systematic review and meta-analysis that screened the following online electronic databases – Cochrane, PubMed and Embase, to identify qualified studies updated up to January 2019. Several literatures that were relevant to the present analysis were also included. Overall, 14 RCTs with 4,998 patients in the tiotropium group and 5,074 patients in the control group were selected. The findings showed that tiotropium was significantly associated with improved morning peak expiratory flow (PEF), evening PEF, peak forced expiratory volume (FEV) and trough FEV relative to the control group. However, no significant difference was observed in peak FVC, trough FVC, acute exacerbations (AE) and serious AE between the two groups. Therefore, the results highlighted the significant effect of tiotropium in treatment of moderate-to-severe asthma, mainly in increasing morning PEF, evening PEF, peak FEV and trough FEV, based on high-quality RCTs. It was stated that more high-quality larger-sample RCTs are needed to gather stronger evidence on the therapeutic efficacy and safety of tiotropium in clinical practice.