Background and Purpose— Diabetes is a common comorbid disease in stroke patients and has a strong influence on stroke-related outcomes, including stroke recurrence. We sought to examine the quality of care and in-hospital outcomes in patients with diabetes in the Get With the Guidelines–Stroke (GWTG-Stroke) program. Methods— Data were obtained from 415 926 ischemic stroke patients from 1070 United States hospitals that participated in GWTG-Stroke between 2003 and 2008. We analyzed the relationships between diabetes and quality of care, in-hospital mortality, and discharge home using multivariable logistic regression. Results— There were 130 817 (31%) ischemic stroke patients with diabetes. Quality of care received by patients with and without diabetes was similar except for intravenous recombinant tissue plasminogen activator (rt-PA) and cholesterol treatment. Fifty-four percent of patients with diabetes who arrived within 2 hours of onset received rt-PA compared to 60.8% of patients without diabetes (adjusted odds ratio [aOR], 0.83; 95% CI, 0.79–0.88). Almost 80% of patients with diabetes were discharged on cholesterol treatment compared to 71% of patients without diabetes (aOR, 1.40; 95% CI, 1.37–1.44). Diabetes patients were less likely to be discharged home (aOR, 0.80; 95% CI, 0.78–0.81) and had a higher risk of in-hospital death (aOR, 1.12; 95% CI, 1.08–1.15). Conclusions— Quality of care among patients with and without diabetes was similar except for rt-PA and cholesterol treatment. Diabetes was associated with worse stroke-related outcomes. Greater quality-improvement efforts to increase the use of rt-PA and other secondary prevention treatments in patients with diabetes are warranted.