Asthma exacerbations can be frequent and range in severity from relatively mild to status asthmaticus. Currently inhaled ß2 agonists are the main stay of therapy for asthmatic patients. Patients resistant to beta agonists are prescribed corticosteroid therapy but this often requires hours to demonstrate significant benefit. Methylxanthines like theophylline have a low therapeutic index and show frequent side effects, making it increasingly unpopular. Studies have shown the role of magnesium sulphate as a bronchodilator. Magnesium may be effective in acute asthma through one or more of a variety of mechanisms such as relaxation of the airway smooth muscle and increase in the bronchodilator response to salbutamol in acute asthma. Nebulized MgSO4 appears to be effective and safe to administer to patients experiencing asthma exacerbations