Background: Anaesthesia teams are temporarily assembled to cooperate with teams in emergency departments in the immediate management of events compromising patients' airway, ventilation and circulation. Purpose: The aim was to describe a temporary ad-hoc anaesthesia team's performance. Design: An observational study was conducted. Methods: Data, collected with 12 non-participatory observations, were analysed using both an thematic method, and a validated assessment tool, the Team Emergency Assessment Measure. Results: Three themes were identified: (1) flexibility in assuming varying roles, (2) expertise in verbal and non-verbal communication and (3) skills dealing with the challenges of working in unfamiliar dynamic environments. Ninety per cent of anaesthesia teams scored 7.6 (0-10) on the overall assessment according to the Team Emergency Assessment Measure rating. Conclusion: Ad-hoc anaesthesia team members communicated in various ways and the anaesthesia team adapted well to the unpredictable environment in the emergency department.