Background: ECG is a useful toot in monitoring vital functions in patients with acute Stroke; however, fairly little evidence is available concerning the prevalence and the prognostic impact of ECG findings in patients with acute cerebral infarction and acute intracerebral haemorrhage (ICH). Methods: This analysis was based on data from 692 patients with acute cerebral infarction, 155 patients with intracerebral haemorrhage (ICH), and 223 patients with transient ischaemic attack (TIA), who were admitted to hospital within 6 h of symptom onset. A 12 lead ECG was obtained on admission, and the patient was on telemetry for the first 12-24 h of hospitalisation. Results: ECG abnormalities were observed in 60% of patients with cerebral infarction, 50%, of patients with ICH, and 44% of patients with TIA. In multivariate analyses 3-month mortality in patients with ischaemic stroke was predicted by atrial fibrillation OR 2.0 (95% CI 1.3-3.1), atrio-ventricular block OR 1.9 (95% Cl 1.2-3.9), ST-elevation OR (2.8, 95% CI 1.3-6.3), ST-depression OR 2.5 (95% CI 1.5-4.3), and inverted T-waves OR 2.7 (95% Cl 1.6-4.6). This was independent of stroke severity, pre-stroke disability and age. In patients with ICH, sinus tachycardia OR 4.8 (95% Cl 1.7-14.0), ST-depression OR 5.2 (95% Cl 1.1-24.9), and inverted T-wave 5.2 (95% CI 1.2-22.5) predicted poor outcome. None of the changes reached significance in patients with TIA. In patients with severe cerebral infarction or ICH, heart rate did not decrease within the first 12 h after admission, which was the case in patients with mild to moderate stroke. Rapid heart rate predicted 3-month mortality in multivariate testing OR 1.7 (95% Cl 1.02-2.7). Conclusions: ECG abnormalities are frequent in acute stroke and may predict 3-month mortality. (c) 2005 Elsevier B.V. All rights reserved.