To determine the feasibility and safety of treatment of acute hypertension in patients with intracerebral hemorrhage within 24 hrs of symptom onset. Elevated blood pressure, observed in up to 56% of patients with intracerebral hemorrhage, may predispose to hematoma expansion; on the other hand, reduction of blood pressure may reduce hematoma expansion and subsequent death and disability. Single-center prospective registry supplemented by retrospective chart review. University-affiliated medical center with dedicated stroke service. All patients admitted to the stroke service with spontaneous intracerebral hemorrhage and acute hypertension within 24 hrs of symptom onset. Patients were treated with intravenous nicardipine within 24 hrs of symptom onset to reduce and maintain mean arterial pressure of <130 mm Hg. The mean arterial pressure goal was consistent with the American Heart Association guidelines. The primary outcome was the tolerability of the treatment as assessed by achieving and maintaining the mean arterial pressure goals for 24 hrs after initiation of intravenous nicardipine infusion. Other end points ascertained were: neurologic deterioration defined by a decline in Glasgow Coma Scale from pretreatment assessment by >or=2 points or increase in National Institutes of Health Stroke Scale score by >or=2 points and hemorrhage growth defined as an increase in the volume of intraparenchymal hemorrhage of >33% as measured by image analysis on the 24-hr computed tomographic scan compared with the baseline computed tomographic scan. Rates of favorable outcome and death were ascertained at 1 month. Of the total 46 patients admitted with intracerebral hemorrhage in our service, 29 patients were treated. Mean age of the treated patients was 58 +/- 13 yrs; ten were women. Initial National Institutes of Health Stroke Scale ranged from 1 to 38. The primary outcome of tolerability was achieved in 25 of the 29 patients (86%). Neurologic deterioration was observed in 4 of 29 patients. Hematoma enlargement was observed in five patients. Favorable outcome (defined as modified Rankin scale of <or=2) and death at 1-month was observed in 11 (38%) and 9 (31%) of the 29 patients, respectively. We observed a high rate of tolerability among patients with intracerebral hemorrhage who were treated with intravenous nicardipine using mean arterial pressure goals defined by American Heart Association guidelines within 24 hrs of symptom onset.