The combination of budesonide and formoterol administered in one hydrofluoroalkane pressurized metered-dose inhaler (pMDI) is approved in the United States in two dosage strengths (budesonide/formoterol pMDI 80/4.5 microg x 2 inhalations [160/9 microg] or 160/4.5 microg x 2 inhalations [320/9 microg]) in a fixed-dose, twice-daily regimen for the treatment of patients > or =12 years old with persistent asthma not adequately controlled with an inhaled corticosteroid (ICS) alone. This article reviews the clinical profile of budesonide/formoterol pMDI in patients with persistent asthma, including information on pharmacogenetics, efficacy, and tolerability. Studies of budesonide/formoterol pMDI in patients with asthma were identified through PubMed and respiratory meeting abstract databases. Budesonide/formoterol pMDI 160/9 microg has shown a rapid onset (within 15 minutes) of clinically significant bronchodilation that is faster than fluticasone propionate/salmeterol dry powder inhaler (DPI) 250/50 microg (within 30 minutes). The efficacy and tolerability profile of budesonide/formoterol pMDI 320/9 microg was similar to fluticasone propionate/salmeterol DPI 250/50 microg and budesonide/formoterol DPI 320/9 microg in adults and adolescents with persistent asthma. Short-term (12-week) and long-term (6- to 12-month) studies have established greater efficacy and similar tolerability of budesonide/formoterol pMDI compared with its monocomponents and placebo in patients with mild/moderate or moderate/severe persistent asthma. Studies evaluating patient-reported outcomes, including health-related quality of life and patient satisfaction with treatment, further support the benefits of budesonide/formoterol pMDI in patients with persistent asthma. In summary, budesonide/formoterol pMDI is an effective, well-tolerated treatment option for patients with persistent asthma for whom ICS/long-acting beta2-adrenergic agonist combination therapy is appropriate.