Background: Treating asthma with a combination of inhaled corticosteroid and a long-acting β-2-agonist is often preferred when asthma is not controlled when using a low-medium dose of an inhaled corticosteroid. Objective: To review the pharmacology, efficacy and safety of inhalers containing combinations of long-acting bronchodilators and inhaled corticosteroids to treat moderate-to-severe, persistent asthma. Methods: Using a list of keywords, we conducted a PubMed search of the literature. Data provided by the manufacturer were also reviewed. Results: Fluticasone propionate with salmeterol and budesonide with formoterol are both well tolerated, have equal clinical efficacy and have recent data affirming their safe use in diverse patient populations. Conclusions: Combination inhalers improve asthma control in patients previously uncontrolled on inhaled corticosteroids.