BACKGROUND: The characteristics, management and outcomes of patients who suffer intracerebral hemorrhage (ICH) while taking oral anticoagulants (OAC) are relatively unreported. DESIGN: Retrospective cohort study of consecutive cases with ICH associated with OAC. SETTING: A university-affiliated tertiary care hospital in Ontario, Canada. PATIENTS/PARTICIPANTS: 368 charts of individuals with a discharge diagnosis of ICH (ICD-9 code 431) between January 1993 and May 1998 were reviewed. MAIN RESULTS: 20 (5.4%, 95% confidence interval (CI): 3.1-7.7%) of the 368 ICHs occurred in people taking OAC. The median age of patients on OAC was 74 years (S.D.+/-9.8), and 70% (95% CI: 49-91%) were female. The median INR at presentation was 3.4 (intraquartile (IQR) range 2.2-4.4). Nine of 20 (45%) patients had INR values which exceeded the target range. The case fatality rate was 45% (95% CI: 23-67%). Approximately 2.8 years after the initial ICH, 9 of the 11 patients who survived the initial ICH were still alive, and 6 had restarted OAC. CONCLUSIONS: ICH is a serious complication in patients taking OAC, and the case-fatality rate is high. Given the increasing use of OAC in patients with cardiovascular disease, the relative benefits and risks of this therapy must be weighed carefully.