To test the resuscitation non-technical Team Emergency Assessment Measure (TEAM) for feasibility, validity and reliability, in two Australian Emergency Departments (ED).Non-technical (teamwork) skills have been identified as inadequate and as such have a significant impact on patient safety. Valid and reliable teamwork assessment tools are an important element of performance assessment and debriefing processes.A quasi experimental design based on observational ratings of resuscitation non-technical skills in two metropolitan ED. Senior nursing staff rated 106 adult resuscitation team events over a ten month period where three or more resuscitation team members attended. Resuscitation events, team performance and validity and reliability data was collected for the TEAM.Most rated events were for full cardiac resuscitation (43%) with 3-15 team members present for an average of 45 min. The TEAM was found to be feasible and quickly completed with minimal or no training. Discriminant validity was good as was internal consistency with a Cronbach alpha of 0.94. Uni-dimensional and concurrent validity also reached acceptable standards, 0.94 and >0.63 (p=<0.001), respectively, and a single 'teamwork' construct was identified. Non-technical skills overall were good but leadership was rated notably lower than task and teamwork performance indicating a need for leadership training.The TEAM is a feasible, valid and reliable non-technical assessment measure in simulated and real clinical settings. Emergency teams need to develop leadership skills through training and reflective debriefing.