BACKGROUND: Intracerebral hemorrhage (ICH) causes higher morbidity and mortality than other forms of stroke and has no proven effective treatment. Hematoma volume is a powerful predictor of outcome after ICH. SUMMARY OF REVIEW: Historically, ICH bleeding was considered to be a monophasic event that stopped quickly as a result of clotting and tamponade by surrounding brain tissue. More recently, prospective and retrospective CT-based studies have demonstrated that hematoma growth occurs in up to 38% of patients initially scanned within 3 hours of onset and in 16% scanned between 3 and 6 hours, even in the absence of coagulopathy. Progressive bleeding of this type has been associated with contrast extravasation on CT angiography and poor outcome after early (<4 hours) surgical clot evacuation. On the basis of these observations, it is plausible that ultra-early hemostatic therapy given in the emergency setting might reduce ICH volume in some patients and improve outcome. Among candidate agents for this indication, the most promising is recombinant activated factor VIIa, which promotes local hemostasis at sites of vascular injury in both coagulopathic and normal patients. CONCLUSIONS: Ultra-early hemostatic therapy, given within 3 to 4 hours of onset, may potentially arrest ongoing bleeding and minimize hematoma growth after ICH. Given the current lack of effective therapy for ICH, clinical trials testing this treatment approach are justified.