Albumin concentration in cerebrospinal fluid (CSF) and plasma was determined in 44 cadavers divided into three groups on the basis of death agony duration. The same was determined in a control group of 42 patients with no demonstrable neurological disease. Following Schuller's method, the evaluation of the blood CSF barrier permeability was based upon the rate of albumin transfer from plasma to CSF. An average increase of 9% in blood CSF barrier permeability was found in cases of a long-duration death agony but not in cases of short-duration death agony (sudden deaths) or in the control group. We consider these results to be related to the hypoxia and hypercapnia which characterize the agonic suffering period. Therefore, we conclude that the postmortem determination of the rate of albumin transfer from plasma to CSF could be a reliable indicator of the duration of the agonic process.