Novel derivatives of lysophingolipids free from sialic acids which are N-acyllysosphingolipids having one of the two formulae: ##STR1## in which -A- stands for the group --CH.dbd.CH-- or --CH.sub.2 --CH.sub.2 --, n.sub.1 is a whole number of between 6 and 18, n.sub.2 is a whole number of between 11 and 15, X is a hydrogen atom or the residue of a monosaccharide or a disaccharide or phosphorylcholine and R represents an alkyl radical derived from a saturated or unsaturated aliphatic carboxylic acid having from 2 to 24 carbon atoms substituted by one or more polar groups. The lysosphingolipid derivatives of the invention exhibit an inhibiting action on protein-kinase C activation and, thus, can be utilized in therapies for various pathologies of the nervous system.