Data on the use of paper electrophoresis in the study of cerebrospinal fluid proteins are reviewed as to show the importance of this method for the clinical laboratory. The mean of protein fractions concentration as well as the references concerning to pathologic findings are presented and discussed. The main aspects of contributions in this field are discussed, showing the aid brought by the protein electrophoretic studies to the physiopathology of cerebrospinal fluid and to pathogenetic interpretations of some nervous diseases.