We report our experience of stroke in 136 young adults aged from 18 to 45 years seen in the Eastern Province of Saudi Arabia over a 10-year period. They constituted 25% of all our stroke cases. Thirty-eight percent were Saudi nationals and 62% expatriates. Males largely outnumbered females. The frequency of cerebral infarction (54%) was not very different from that of intracranial hemorrhage (45%). Atherosclerosis and embolism of cardiac origin were the major causes of infarction. The main causes of intracranial bleeding were arterial aneurysms, arteriovenous malformations and hypertension. However, the causes of 29% of ischemic strokes and 44% of hemorrhagic ones remained undetermined. Interethnic comparison of the causes showed that hemorrhages were significantly more frequent in Far East immigrants. Sixty five percent of cerebral infarctions in Asiatic patients remained of undetermined origin. The local variant of sickle cell gene did not seem to play a major role in the pathogenesis of stroke in the Saudi young adult. These data are commented and compared with similar reported data. The influence of the demographic structures of the Saudi population and immigrants communities is analyzed.