Epidemiological studies have shown a consistent downward trend in the incidence and mortality of stroke in industrialized communities. There are however no reports on the pattern of stroke in Saudi nationals and expatriates in Saudi Arabia. The types and etiologies in 372 subjects (262 Saudis, 110 non-Saudis) are described. Males outnumbered females in the ratios of 2.2:1 and 8.2:1 for Saudis and non-Saudis, respectively. The frequency of stroke increased steadily with age until the 7th decade in Saudis but dropped sharply after the 6th in expatriates. The frequency of stroke types in Saudis was ischemic (61%), hemorrhagic (17%) and unspecified (22%) as against 46, 47, and 7% respectively in non-Saudis. Intracerebral hemorrhage was more frequent than subarachnoid hemorrhage (SAH) and was encountered more often in Saudis than in non-Saudis; SAH was 3 times more common in expatriates than in Saudis. The major predisposing factors for stroke were hypertension, diabetes mellitus, and cardiac disorders. Abnormal hemoglobinopathies, especially sickle cell anemia, were rare. The differences observed in the age and sex distribution and in the stroke pattern between Saudi nationals and expatriates most likely reflect the demographic structure existing in Saudi Arabia.