Troponin I levels were drawn within 24 hours of stroke in 161 of 175 patients (92%) with ischemic stroke, 94 of 107 patients (88%) with intracerebral hemorrhage, and 96 of 96 patients (100%) with subarachnoid hemorrhage. A troponin level >0.4 ng/ml was considered increased. In patients with ischemic stroke, in-hospital mortality occurred in 15 of 23 patients (65%) with increased troponin I compared with 6 of 138 patients (4%) with normal troponin I (p <0.001). In patients with intracerebral hemorrhage, in-hospital mortality occurred in 9 of 14 patients (64%) with increased troponin I compared with 22 of 80 patients (28%) with normal troponin I (p <0.005). In patients with subarachnoid hemorrhage, in-hospital mortality occurred in 8 of 20 patients (40%) with increased troponin I compared with 8 of 76 patients (11%) with normal troponin I (p <0.005). In conclusion, patients with ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage with elevated troponin I levels have increased in-hospital mortality.