Introduction. Diabetes mellitus (DM) is an important risk factor in cerebral vascular disease since it causes endothelial proliferation and thickening of the plasmatic membrane in the small blood vessels. The pathogenic mechanism is thus different from that of athero-thrombosis or emboli. Our objective was to determine whether there are differences between strokes in diabetic patients and strokes secondary to other diseases. Patients and methods. We made a prospective study of 415 stroke patients admitted to hospital consecutively over one year. Transient ischaemia and subarachnoid hem- orrhage were excluded. We analysed age, sex, risk factors, severity (Canadian scale), mortality and functional prognosis one week later. Results. Of the 415 patients, 354 were diagnosed as having cerebral infarcts and 61 parenchymatous hemorrhage. The average age was 72.2 years. The commonest risk factor was arterial hypertension (n= 241). There were 95 patients with DM. Bivariate and multivariate analysis showed independent variables associated with DM to be the onset of cerebrovascular pathology at a younger age (p= 0.009), association with arterial hypertension (p= 0.002) and poor previous quality of life (p= 0.003). We did not find a higher incidence of lacunar infarcts amongst the diabetic patients. Conclusions. The diabetic patient is younger and often also has arterial hypertension. There was no difference in mortality or type of stroke (ischemic compared with hemorrhagic). No significant relationship was found with lacunar infarcts.