The Mega Code is a simulated cardiac arrest during which students practice as members of a team and learn to integrate the knowledge and skills of advanced cardiac life support (ACLS). This study used the Mega Code and American Heart Association (AHA) standards to evaluate 32 medical residents (MDs) and nine critical care nurses (RNs) in the role of ACLS team leader. All had been previously trained in ACLS. The testing sequence included ventricular fibrillation (VF) refractory to initial countershock (defib), asystole after second defib, recurrent VF after drug therapy, and finally sinus rhythm after third defib. A blood gas report indicated respiratory acidosis and hypoxemia. Assessment of patient status was poor in both groups, although MDs did significantly (p = .001) better than RNs. Other problem areas were drug therapy and troubleshooting, with no differences between MDs and RNs. These results indicate that assessment and troubleshooting are not adequately stressed in the AHA ACLS curriculum; moreover, there is no lecture that specifically addresses the team approach to resuscitation and the role of team leader. We found that the Mega Code effectively evaluated individual and group performance. Results of objective-based Mega Code testing can be used both to improve ACLS curriculum and to indicate areas to be stressed during refresher training.