Measurements of CSF-albumin, and S/CSF-albumin in two groups of patients with small and large infarcts failed to show BBB damage to albumin in about one half of the patients. No significant difference was found between the two groups of patients in regard to the above-mentioned parameters. The localization of the infarcts (close to the CSF or deep in the brain) did not influence the S/CSF-albumin. No correlation was found between the S/CSF-albumin and the time interval between the onset of the stroke and the lumbar puncture within 96 h. Some suggestions are put forward to explain the discrepancies between the CT-scan and S/CSF-albumin in the assessment of BBB damage.