The Cobra Perilaryngeal Airway (Engineered Medical Systems, Indianapolis, IN) is a new supraglottic airway designed for spontaneous and controlled ventilation. It is not yet commercially available in the UK. Our aim was to evaluate the performance of the Cobra Perilaryngeal Airway in a cohort study and in a randomised, controlled, crossover comparison study with the Classic Laryngeal Mask Airway. After studying 29 patients, both studies were suspended and later stopped after two cases of significant pulmonary aspiration had occurred in patients whilst using the Cobra Perilaryngeal Airway. These cases raised concern about both the design and the safety of the Cobra Perilaryngeal Airway, particularly during controlled ventilation. We suggest that the Cobra Perilaryngeal Airway should not be marketed for controlled ventilation until more safety data are available.