Background and Purpose-Guidelines recommend oral anticoagulation for ischemic stroke patients with atrial fibrillation, and previous studies have shown the underuse of anticoagulation for these patients in China. We sought to explore the underlying reasons and factors that currently affect the use of warfarin in China. Methods-From June 2012 to January 2013, 19 604 patients with acute ischemic stroke were admitted to 219 urban hospitals voluntarily participating in the China National Stroke Registry II. Multivariable logistic regression models using the generalized estimating equation method were used to identify patient/hospital factors independently associated with warfarin use at discharge. Results-Among the 952 acute ischemic stroke patients with nonvalvular atrial fibrillation, 19.4% were discharged on warfarin. The risk of bleeding (52.8%) and patient refusal (31.9%) were the main reasons for not prescribing anticoagulation. Larger/teaching hospitals were more likely to prescribe warfarin. Older patients, heavy drinkers, patients with higher National Institutes of Health Stroke Scale score on admission were less likely to be given warfarin, whereas patients with history of heart failure and an international normalized ratio between 2.0 and 3.0 during hospitalization were significantly associated with warfarin use at discharge. Conclusions-The rate of warfarin use remains low among patients with ischemic stroke and known nonvalvular atrial fibrillation in China. Hospital size and academic status together with patient age, heart failure, heavy alcohol drinking, international normalized ratio in hospital, and stroke severity on admission were each independently associated with the use of warfarin at discharge. There is much room for improvement for secondary stroke prevention in nonvalvular atrial fibrillation patients in China.