A method for obtaining crystals of ammonium dinitroamide, ADN, comprising: - providing, at a temperature from between room temperature and 65°C, an ADN solution in a polar solvent for the ADN; said ADN solution, consisting essentially of said ADN, of said polar solvent for the DNA and optionally of at least one nonionic surfactant, containing the ADN in a weight ratio, ADN/polar solvent, of at least 15%; - providing, at a temperature below said temperature of said ADN solution, of a non-polar solvent which is a non-solvent for the ADN, and is miscible with said polar solvent for the AND, to which at least one nonionic surfactant has been optionally added; - adding, with stirring, at least a part of said ADN solution to at least a part of said non-polar solvent to which at least one nonionic surfactant has been optionally added, said at least a part of said ADN solution being added to said at least a part of said non-polar solvent to which at least one nonionic surfactant has been optionally added, at most in an amount corresponding to a weight ratio of polar solvent /(polar solvent + non-polar solvent) of 25%, advantageously in an amount corresponding to such a weight ratio of 8 to 23%, very advantageously in an amount corresponding to such a weight ratio of 9 to 17%, to form an ephemeral emulsion of droplets of said ADN solution in said non-polar solvent to which at least one nonionic surfactant has been optionally added; said droplets, due to the inter-diffusion of the miscible polar and non-polar solvents (S1 and S2), transforming into the expected ADN crystals; said at least one nonionic surfactant being present in said ADN solution and/or having been added to said non-polar solvent, advantageously being present in said ADN solution, in an amount effective for forming said ephemeral emulsion; - the recovery of said crystals, and generally - the drying of said recovered crystals. - providing, at a temperature from between room temperature and 65°C, an ADN solution in a polar solvent for the ADN; said ADN solution, consisting essentially of said ADN, of said polar solvent for the DNA and optionally of at least one nonionic surfactant, containing the ADN in a weight ratio, ADN/polar solvent, of at least 15%; - providing, at a temperature below said temperature of said ADN solution, of a non-polar solvent which is a non-solvent for the ADN, and is miscible with said polar solvent for the AND, to which at least one nonionic surfactant has been optionally added; - adding, with stirring, at least a part of said ADN solution to at least a part of said non-polar solvent to which at least one nonionic surfactant has been optionally added, said at least a part of said ADN solution being added to said at least a part of said non-polar solvent to which at least one nonionic surfactant has been optionally added, at most in an amount corresponding to a weight ratio of polar solvent /(polar solvent + non-polar solvent) of 25%, advantageously in an amount corresponding to such a weight ratio of 8 to 23%, very advantageously in an amount corresponding to such a weight ratio of 9 to 17%, to form an ephemeral emulsion of droplets of said ADN solution in said non-polar solvent to which at least one nonionic surfactant has been optionally added; said droplets, due to the inter-diffusion of the miscible polar and non-polar solvents (S1 and S2), transforming into the expected ADN crystals; said at least one nonionic surfactant being present in said ADN solution and/or having been added to said non-polar solvent, advantageously being present in said ADN solution, in an amount effective for forming said ephemeral emulsion; to form an ephemeral emulsion of droplets of said ADN solution in said non-polar solvent to which at least one nonionic surfactant has been optionally added; said droplets, due to the inter-diffusion of the miscible polar and non-polar solvents (S1 and S2), transforming into the expected ADN crystals; said at least one nonionic surfactant being present in said ADN solution and/or having been added to said non-polar solvent, advantageously being present in said ADN solution, in an amount effective for forming said ephemeral emulsion; - the recovery of said crystals, and generally - the drying of said recovered crystals.