To provide a method for producing a lithium perfluoroalkyl sulfonate, capable of easily producing a highly pure lithium perfluoroalkyl sulfonate with an extremely small amount of impurities.

A method for producing a lithium perfluoroalkyl sulfonate includes: subjecting a metal perfluoroalkyl sulfonate expressed by a chemical formula (C_nF_2n+1SO₃)_m.M (where n is an integer of 1-4, m is 1 or 2, and M is an alkaline metal selected from sodium and potassium or an alkaline earth metal selected from calcium and magnesium) and lithium chloride tpo a salt exchange reaction in presence of an organic solvent; and separating and removing precipitated metal chloride MCl by filtration.