The outcome of critical incidents in the operating theatre has been shown to be influenced by the behaviour of anaesthetic technicians (ATs) assisting anaesthetists, but the specific non-technical skills involved have not been described. We performed a review of critical incidents (n=1433) reported to the Australian Incident Monitoring System between 2002 and 2008 to identify which non-technical skills were used by ATs. The reports were assessed if they mentioned anaesthetic assistance or had the boxes ticked to identify "inadequate assistance" or "absent supervision or assistance". A total of 90 critical incidents involving ATs were retrieved, 69 of which described their use of non-technical skills. In 20 reports, the ATs ameliorated the critical incident, whilst in 46 they exacerbated the critical incident, and three cases had both positive and negative non-technical skills described. Situation awareness was identified in 39 reports, task management in 23, teamwork in 21 and decision-making in two, but there were no descriptions of issues related to leadership, stress or fatigue management. Situation awareness, task management and teamwork appear to be important non-technical skills for ATs in the development or management of critical incidents in the operating theatre. This analysis has been used to support the development of a non-technical skills taxonomy for anaesthetic assistants.