Process for preparing an IZM-2 zeolite, comprising at least the following steps: i) mixing, in aqueous medium, of at least one source of at least one tetravalent element X in oxide form XO 2, at least one source of at least one trivalent element in oxide form Y 2 O 3, a nitrogenous organic compound R 2, which is 1,6-bis(methylpiperidinium)hexane dihydroxide, at least one source of at least one alkali metal M of valency n chosen from alkali metal chlorides, n being an integer greater than or equal to 1, M being chosen from lithium, potassium, sodium and caesium, and the mixture of at least two of these metals, and optionally in the presence of at least one fluoride anion, BF, the reaction mixture having the following molar composition: XO 2 /Y 2 O 3 between 70 and 350, H 2 O/XO 2 between 1 and 100, R 2/ XO 2 between 0.006 and 0.25, M 1/n Cl/XO 2 between 0.005 and 0.5, BF/XO 2 between 0 and 0.25, with X being one or more tetravalent elements chosen from the group formed by the following elements: silicon, germanium, titanium, at least one element X being silicon, Y is one or more trivalent elements chosen from the group formed by the following elements: aluminium, iron, boron, indium and gallium, and at least one element Y being aluminium, until a homogeneous precursor gel is obtained, and BF being chosen from hydrofluoric acid in aqueous solution and fluorine salts in which B is a cation chosen from the cations NH 4 +, Na +, K + and Li +. ii) hydrothermal treatment of said precursor gel obtained on conclusion of step i) at a temperature of between 120°C and 220°C, for a time of between 1 day and 10 days. i) mixing, in aqueous medium, of at least one source of at least one tetravalent element X in oxide form XO 2, at least one source of at least one trivalent element in oxide form Y 2 O 3, a nitrogenous organic compound R 2, which is 1,6-bis(methylpiperidinium)hexane dihydroxide, at least one source of at least one alkali metal M of valency n chosen from alkali metal chlorides, n being an integer greater than or equal to 1, M being chosen from lithium, potassium, sodium and caesium, and the mixture of at least two of these metals, and optionally in the presence of at least one fluoride anion, BF, the reaction mixture having the following molar composition: XO 2 /Y 2 O 3 between 70 and 350, H 2 O/XO 2 between 1 and 100, R 2/ XO 2 between 0.006 and 0.25, M 1/n Cl/XO 2 between 0.005 and 0.5, BF/XO 2 between 0 and 0.25, with X being one or more tetravalent elements chosen from the group formed by the following elements: silicon, germanium, titanium, at least one element X being silicon, Y is one or more trivalent elements chosen from the group formed by the following elements: aluminium, iron, boron, indium and gallium, and at least one element Y being aluminium, until a homogeneous precursor gel is obtained, and BF being chosen from hydrofluoric acid in aqueous solution and fluorine salts in which B is a cation chosen from the cations NH 4 +, Na +, K + and Li +. XO 2 /Y 2 O 3 between 70 and 350, H 2 O/XO 2 between 1 and 100, R 2/ XO 2 between 0.006 and 0.25, M 1/n Cl/XO 2 between 0.005 and 0.5, BF/XO 2 between 0 and 0.25, with X being one or more tetravalent elements chosen from the group formed by the following elements: silicon, germanium, titanium, at least one element X being silicon, Y is one or more trivalent elements chosen from the group formed by the following elements: aluminium, iron, boron, indium and gallium, and at least one element Y being aluminium, until a homogeneous precursor gel is obtained, and BF being chosen from hydrofluoric acid in aqueous solution and fluorine salts in which B is a cation chosen from the cations NH 4 +, Na +, K + and Li +. ii) hydrothermal treatment of said precursor gel obtained on conclusion of step i) at a temperature of between 120°C and 220°C, for a time of between 1 day and 10 days.