The purpose of this study was to estimate the risk factors, early course, outcome and neuroimaging patterns in primary intracerebral hemorrhages (PIH). Using the Besançon Stroke Registry, 350 patients with first PIH documented by computed tomography (CT) between 1987 and 1993 were included in the present study. Patients with hemorrhage secondary to traumatism, brain tumor, thrombolytic treatment, vascular malformation or with hemorrhagic infarction were excluded. All CTs were evaluated to define the location, extension and volume of bleeding (55% of CT were performed within the first 12 h). Causes of death were classified and the 30-day outcome survival was evaluated with a modified Rankin scale (40 patients underwent a noncodified surgical procedure and were excluded from the outcome evaluation). Locations were lobar (36.5%), lenticular (32%), thalamic (15.7%), cerebellar (8.8%), midbrain and pons (2%), intraventricular (2%), caudate (1%) and multiple (2%). Risk factors included hypertension (54.8%), alcohol (18%) anticoagulant treatment (8.8%) and none (31.2%). The largest mean volume was in putaminal (41.7 ml) and lobar (39.8 ml) locations. Among 191 patients admitted before the 12th hour of evolution, 51 (26.7%) experienced an early clinical worsening. In this group, the percentage of patients with anticoagulant treatment (19.6%) was significantly higher (p < 0.0001). PIH enlargement was documented in 3 patients. Overall, the 30-day mortality rate was 24.2% with 48% of all deaths occurring in the first 3 days. Death and 30-day survival status were closely associated with PIH volume (p < 0.0001). Our study provides information on the natural history of PIH and especially on initial evolution. PIH volume seems to be an interesting indicator for death and functional status at 30 days.