The presence of acute reversibility to bronchodilators does not distinguish asthma from COPD. Patients with either condition can benefit from bronchodilators, and should be given a trial to assess their response. Some respond with a change in lung volume with less hyperinflation; others improve their forced inspiratory flow and become much more comfortable. The combination of long-acting β-agonists (LABAs) and inhaled steroids is useful in both conditions. While anticholinergics seem to yield the best results in COPD, some patients with asthma benefit from their use. Tiotropium may be the most effective agent as monotherapy in COPD, but the combination of an inhaled steroid and a LABA may produce similar results in improving lung function. Long-acting bronchodilators are effective agents as monotherapy in COPD, but in asthma should be combined with a controller medication. Short-acting β-agonists should be used intermittently in asthma, but may be used regularly or combined with an anticholinergic in COPD. The roles of stereoisomers, leukotriene receptor antagonists, and type 4 phosphodiesterase inhibitors in asthma and COPD remain uncertain at this time.