This retrospective study was conducted to assess Taiwanese emergency physicians for their preference in management and adherence to guidelines in treating patients with acute exacerbation of asthma. One hundred twenty patients from hospitals of three different levels were evaluated by reviewing their medical records. Our study revealed that physicians from medical centers and regional hospitals assessed patients more often with arterial blood gas or pulse oximetry; prescribed more doses of beta2-agonist nebulizers; administered more doses of beta2-agonist nebulizers before administering parenteral aminophylline; and prescribed ipratropium nebulizers more often as adjunctive therapy. On the other hand, physicians from district hospitals more frequently prescribed parenteral aminophylline as the first-line medication and more often prescribed only a single dose of beta2-agonist nebulizer. Most emergency physicians in Taiwan did not adhere to guidelines. Specifically, these included omission of peak expiratory flow as the means to assess the severity of asthma exacerbation and response to treatment; suboptimal use of inhaled bronchodilators, such as beta2-agonists and ipratropium; and inappropriate use of parenteral aminophylline as the first-line medication.