To evaluate the risk factors of cerebral infarction, a case-control study was conducted in rural areas of Okayama prefecture that are rapidly urbanizing. The results of an interview focusing on psychological stress and stress response scales, questionnaires on life styles and mass health examinations were analyzed by conditional logistic regression methods. The results were as follows : 1. Psychological stress, smoking, hypo-HDL-cholesterolemia, hypercholesterolemia and high grade preference for fat were identified as new risk factors of cerebral infarction in rural areas in addition to known risk factors such as hypertension, glucose intolerance, atrial fibrillation and high consumption of rice and salt. 2. High consumption of salt, diastolic high blood pressure and hypo-HDL-cholesterolemia were strongly related to an increased risk of cerebral infarction. 3. The age at onset of cerebral infaction was noted to be increased because the odds ratios were high for systolic blood pressure as well as diastolic blood pressure. 4. Tatgets for strategies of preventive medicine for cerebral infarction are needed giving attention to the risk factors such as increased psychological stress, smoking that reflect modern life style chages in rural areas.