Acute exacerbation of bronchial asthma is a major factor associated with high morbidity and mortality at presentation in the Emergency Department. Short acting beta-2 agonist is used to provide quick relief in patients with asthmatic symptoms, and are the most potent bronchodilators currently available to relieve bronchoconstriction during acute asthmatic attacks. We aimed to look at the response of short acting beta-2 agonist (salbutamol) as a bronchodilator during acute exacerbation of bronchial asthma and to correlate the severity of asthmatic exacerbation with beta-2 adrenergic receptor polymorphism.