A total of 48 patients presenting to the emergency department as acute asthma exacerbation were prospectively studied. Rhinolaryngoscopy was conducted with simultaneous flow measurements and spirometry performed before and after the procedure. Measurements of the vocal cord opening during various phases of respiration were analyzed. Only 4 of 48 patients had anterior two-thirds closure of the vocal cords with a diamond-shaped opening posteriorly during expiration. One additional patient had inspiratory and expiratory closure of the vocal cords. The previously unreported high incidence of anterior two-thirds closure (10.4%) of the vocal cords suggests that the upper airway has a role to play in a significant number of patients presenting with symptoms of asthma exacerbation.