Background and Purpose-Data supporting the efficacy of stroke center characteristics are limited. Methods-A questionnaire detailing stroke treatment practices was sent to 42 academic medical centers in the University Health Systems Consortium. In-hospital mortality of all emergency department admissions for ischemic stroke at these institutions was evaluated in a database of discharge abstracts during 1997-1999. Institutional characteristics were evaluated as predictors of in-hospital mortality after adjustment for age, sex, race, hospital treatment volume of ischemic stroke, and admission status (emergent, urgent, elective). Length of stay (LOS), total hospital charges, and frequency of tissue plasminogen activator (tPA) administration were evaluated as secondary outcomes. We used a multivariable method called generalized estimating equations, which broadens confidence intervals to adjust for clustering of variables at institutions. Results-Thirty-two institutions completed the questionnaire, and 29 of these were included in the database of discharge abstracts. In-hospital deaths occurred in 758 (7.0%) of the 10 880 ischemic stroke patients admitted through the emergency department. In-hospital deaths were less frequent at hospitals with a vascular neurologist (odds ratio