BACKGROUND Inhaled β-agonists are the cornerstone of acute treatment for asthma and chronic lung disease. Upon emergency department (ED) discharge, patients optimally receive prescriptions for metered-dose inhalers (MDIs) with instructions on their proper use. Yet prior studies suggest that ED personnel have limited knowledge of proper MDI techniques. It is unclear how effectively brief education will improve this knowledge to enable them to provide adequate patient instructions. OBJECTIVE Our aim was to evaluate ED medical personnel's baseline knowledge of MDI use and the utility of brief education on their ability to use MDIs. METHODS After providing written consent, a spirometry nurse evaluated emergency physicians and nurses on their ability to properly perform three (open-mouth/two-finger, spacer, and closed-mouth) MDI techniques. The same spirometry nurse then gave a short educational session demonstrating the proper MDI techniques. Two weeks later, the nurse re-evaluated the same personnel on their MDI techniques. RESULTS All emergency medical personnel initially performed poorly in demonstrating proper MDI technique, averaging 29.8% steps done correctly. Two weeks after their educational session, they improved greatly, averaging 89.4% steps done correctly. CONCLUSIONS This study demonstrated both that ED personnel had poor initial knowledge about MDI techniques and that a brief educational intervention improved most people's ability to use, and presumably to instruct patients/parents in proper use of, MDIs.