Asthma is among the most common ED diagnoses. Asthma exacerbations are generally treated by medications that cause bronchodilation and those that reduce airway inflammation. The effect of alcohol on asthma has been studied by investigators with mixed results. Some studies have reported that alcohol has a beneficial effect on asthma; others report worsening of symptoms. It has been suggested in some quarters that additives in alcoholic drinks cause bronchoconstriction and that pure ethanol has a salutary effect on asthma. If further research bears out this supposition, ethanol may play a limited therapeutic role in asthma that is refractory to other therapy. Emergency physicians should counsel asthmatic patients to avoid alcoholic beverages because they may cause an exacerbation of asthma.