An experimental model of cerebral infarction is created in rats by intracarotid injection of their homologous blood clots. This is the first small animal model in which embolization was achieved by homologous blood clots. The infarcts were produced predominantly in the territory of the middle cerebral artery. The low mortality rate and excellent reproduction rate make possible the correlative study of morphological, biochemical, and metabolic parameters at selected points in time to reconstruct the pathogenesis and natural history of focal cerebral ischemia and its relation to blood elements.