Pure monosialoganglioside GM1 in the form of its sodium salt. There is provided, in particular a monosialoganglioside GM1 having a purity of 99.0% or more produced according to a process comprising (a) separation of GM1 from a lipidic mixture containing the monosialoganglioside GM1 as the main ganglioside component by ion exchange column-chromatography using an eluent comprising potassium or caesium ions, (b) recovery of the solute from the eluted solution, (c) diafiltration of an aqueous solution of the recovered solute, and (d) second diafiltration after the addition of 1 M NaCl, and recovering GM1.
