The invention relates to a joint method of producing fatty nitriles and/or amines and dialkyl carbonates of formula R1O-CO-OR1 in which R1 comprises from 1 to 4 carbon atoms, starting from an ester of a saturated or unsaturated fatty acid derived from natural oils comprising the following zones: I) a zone for synthesis of a nitrile/amine comprising the following steps: a) optional conversion firstly by hydrolysis of the fatty acid ester derived from an oil of natural origin, to fatty acid simultaneously producing the alcohol R1OH which is recovered and sent to zone III, followed by b) ammoniation with ammonia of the fatty acid resulting from step a) and/or of the fatty acid ester to a nitrile respectively producing an ammonia/water mixture and/or an alcohol/ammonia/water mixture which are sent to zone IV, then by c) hydrogenation of the nitrile resulting from step b), optionally in the presence of ammonia, converting the nitrile to the corresponding amine, II) zone for synthesis of a carbonate of a monoalcohol by reaction of urea with the alcohol R1OH, the reaction of said alcohol with urea also producing ammonia, III) zone for recovery and purification of the alcohol R1OH which is used to supply zone II, IV) zone for recovery of the ammonia from zones I and II in order to be used as a supply for the ammoniation of step b) and optionally the hydrogenation of step c) in zone I.