Objectives : Quantitative evaluation of upper airway obstruction cannot be commonly performed under acute dyspnea, especially in head and neck cancer (HNC); the decision whether or not to perform airway control surgery may be difficult to reach. Peak inspiratory flow (PIF) has been previously demonstrated to be a useful tool to decide on decannulation after HNC surgery. The aim of the present study was to assess the role of PIF as a standardized non-invasive tool in quantifying severe inspiratory dyspnea requiring emergency tracheostomy. Materials and methods : A single-center prospective observational pilot study analyzed PIF measurements in 22 patients exhibiting acute dyspnea due to upper airway obstruction. Main outcome measures : The decision whether or not to perform tracheotomy was taken prior to PIF measurement. PIF was measured with a hand-held PIF meter (In-Check method), and laryngeal fiberoscopy was then performed. Obstruction severity was defined by PIF values. Results : PIF could be measured prior to tracheotomy (imminent in 21 cases, postponed in 1) in all cases. PIF values below 53.1 L/min (i.e., 18.3% of theoretic value) correlated with necessity for emergency tracheotomy. This threshold is concordant with that previously found for the feasibility of decannulation (60 L/min). Conclusions : PIF is a non-invasive quantitative parameter assessing severity of upper airway obstruction, that may be helpful in decision-making for tracheostomy. Testing is simple, quick and reproducible.