The possible influences of cerebral microbleeds (CMBs) on the development of intracerebral hemorrhage (ICH) in patients with leukoaraiosis (LA) have rarely been examined. We aimed to determine whether CMBs might be a risk factor for ICH in hypertensive patients with leukoaraiosis. We studied 70 hypertensive patients with acute ICH and LA (the ICH group) by brain MRI, including T2*-weighted gradient-echo sequences. The control group was composed of 73 hypertensive LA patients without ICH. CMBs and old lacunae were counted in the group of patients with ICH and in the control subjects and compared. The ICH group contained more patients with CMBs (68 patients; control group, 41; p < 0.01), and showed a higher mean number of lesions (19.9 +/- 31.1; control group, 7.4 +/- 19.6; p < 0.01). The negative predictive value for ICH was highest among the ICH patients without CMB (94.1%), and the positive predictive value was highest among the ICH patients with 6 or more CMBs (75.4%). Old lacunae were observed more frequently in the ICH group (65 patients; control group, 58; p = 0.02), but their predictive value for ICH was not high (positive, 52.3%; negative, 75.0%). Our results indicated that CMBs may be used to predict the risk of ICH in hypertensive patients with advanced LA.