OBJECTIVE: To compare Emergency Severity Index (ESI) triage levels and Simple Triage and Rapid Treatment (START) triage colors for urgent care and hospitalization. DESIGN: Cross sectional. SETTING: Inner city emergency department (ED). PARTICIPANTS: Patients years transported by Emergency Medical Services (EMS) participating in the state triage tag exercise, October 9-15, 2011. INTERVENTIONS: EMS assigned each patient a START triage tag. ED staff recorded tag number and color. Demographics, vital signs, 22 emergent interventions, and disposition were obtained via chart review. Institutional review board approval was obtained. MAIN OUTCOME MEASURES: Presence of more than two abnormal vital sign on arrival and need for more than one emergent intervention in ED were considered indicators of acuity and severity. START triage colors were recategorized as urgent (Red, Yellow) and less acute (Green, White), and ESI was recategorized as urgent (1, 2, 3) and less acute (4, 5). RESULTS: Both ED and EMS staff were blinded to the study, and 95% confidence intervals were presented for statistical significance. Of 233 participants, START triage colors were Black=0, Red=12 percent, Yellow=26 percent, Green=53 percent, and White=9 percent. ESI triage levels were level 1=1 percent, level 2=34 percent, level 3=51 percent, level 4=14 percent, and level 5=1 percent. ESI (1, 2, 3) identified 88 percent (75-95 percent) of 49 patients with abnormal vital signs; START (Red, Yellow) only identified 51 percent (35-64 percent). Twenty-one patients needed emergent intervention. ESI (1, 2, 3) identified 95 percent (76-99 percent) of these patients; START (Red, Yellow) identified 33 percent (17-55 percent). ESI (1, 2, 3) identified 98 percent of the 96(92-100 percent) admitted patients; only 48 percent (38-58 percent) were tagged START (Red, Yellow). CONCLUSION: ESI better identified patients with abnormal vital signs, those who needed emergent interventions, and those admitted than START.