The benefit of intravenous thrombolytic therapy in acute brain ischemia is strongly time dependent. The Get With the Guidelines-Stroke database was analyzed to characterize ischemic stroke patients arriving at hospital Emergency Departments within 60 minutes of the last known well time from April 1, 2003, to December 30, 2007. During the 4.75-year study period, among 253 148 ischemic stroke patients arriving directly by ambulance or private vehicle at 905 hospital Emergency Departments, 106 924 (42.2%) had documented, exact last known well times. Onset to door time was 180 minutes in 42 846 (40.1%). Features most strongly distinguishing the patients arriving at 180 minutes were greater stroke severity (median National Institutes of Health Stroke Scale score, 8.0 vs 6.0 vs 4.0, P<0.0001) and more frequent arrival by ambulance (79.0%. vs 72.2% vs 55.0%, P<0.0001). Compared with patients arriving at 61 to 180 minute, "golden hour" patients received intravenous thrombolytic therapy more frequently (27.1% vs 12.9%; odds ratio=2.51; 95% CI, 2.41-2.61; P<0.0001), but door-to-needle time was longer (mean, 90.6 vs 76.7 minutes, P<0.0001). A door-to-needle time of