STUDY OBJECTIVE We compared 2 models of physician leadership for inhospital cardiac arrest teams (CATs): emergency medicine (EM) residents and staff hospitalist physicians. METHODS A before-after study was conducted on all adult inhospital CAT activations over a 2-year period. The primary outcome was return of spontaneous circulation (ROSC). RESULTS There were 749 total code blues during the 2-year study period. Ninety-one were excluded by protocol. EM residents directed 288 codes, hospitalists directed 248 codes, and other specialties directed the remaining 62. There was no statistically significant difference in percent ROSC or survival to hospital discharge. EM residents responded first for 59.2% of the codes compared with a first response rate of 28% for hospitalists (P<.05). Time to achieve ROSC was quicker in the EM resident cohort. CONCLUSION Our findings validate the use of a 24-hour EM resident staffing model for CAT response to inhospital cardiac arrests.