Forty patients were studied by computerized tomography and by radionuclide brain imaging. The final diagnosis was infarction in 29 patients, intracerebral hematoma in seven, acute SAH in one, and old cerebrovascular accidents in three. CT was far superior to RN in detecting intracerebral hematomas and distinguishing them from cerebral infarction. The results of CT and RN tests were comparable regarding the percentage of abnormalities. However, the results in the same patients were not identical in 55% of the cases, indicating a complementary role for the two tests. There was no relationship between the frequency of abnormalities on CT and the time lapse afte the onset of cerebral infarction. RN uptake was not seen in patients with old cerebrovascular accidents.