Uncontrolled asthma results in decreased quality of life, increased healthcare utilization, and significant economic burden. Although current treatments for asthma have improved the level of asthma control, patients with severe persistent and refractory asthma do not achieve adequate disease control despite maximal medical therapy. Bronchial thermoplasty (BT) was developed as a novel device-based approach for the treatment of this subgroup of patients. Since 2005, clinical studies of BT have helped identify suitable candidates for the procedure, define procedure-related adverse events, and quantify meaningful patient outcomes. This chapter details appropriate patient selection, explains how BT is performed and monitored, and reviews the growing body of evidence supporting its use.