Cisternal or lumbar cerebrospinal fluid (CSF) specimens of 59 healthy persons were examined for differential cell count with a new improved sedimentation chamber, similar to that one of Sayk. The purpose of this study was to compare our results to those already described in the literature. Techinical care was taken in order to increase the accuracy of this investigation and it consisted mainly of counting all the existing cells in the preparation, and not only 100 cells or a lesser number, recorded in percentage. The results of this survey have shown that the normal mean values for the CSF cytomorphology are 58.8 per cent lymphocitic cells, 41.0 per cent monocytoid cells, and 0.2 per cent neutrophilic granulocytes. These figures are in good agreement with those already reported by numerous authors, when we consider the lymphocytic and monocytoid cells, but they revealed a fact seldom seen reported: the possibility of a few neutrophilic granulocytes as a constituent of the normal CSF cytomorphology.