The present invention relates to a method for the hydrocyanation of organic ethylenically unsaturated compounds including at least one nitrile function. The invention specifically relates to a method for the hydrocyanation of a hydrocarbon compound including at least one ethylenic unsaturation by a reaction with hydrogen cyanide in a liquid medium and in the presence of a catalyst including a metal element selected from the transition metals and an organophosphorous ligand, the organophosphorous ligand including a compound of general formula (I), where R1 and R2, which are identical or different, are a linear or branched alkyl radical having 1-12 carbon atoms, which can include heteroatoms, or an optionally substituted aromatic or cycloaliphatic radical that can include heteroatoms, wherein the covalent bond between P and R1, and that between P and R2, are P—C bonds.