The process for the production of carnitine hydrochloride which involves placing an ester of .gamma.-halo-acetoacetic acid having the formula: ##STR1## wherein R.sub.1 is hydrogen, R.sub.2 is a lower alkyl group having 1 to 10 carbon atoms and X is a halogen atom selected from the group consisting of chlorine or bromine, in an aqueous solution of excess trimethyl amine held at a temperature between 0.degree. and 50.degree. C., a reaction resulting between said ester and said amine. The excess trimethyl amine is distilled off. The pH of the solution is adjusted between 4 and 8, (3-carbalkoxy-2-oxopropyl)-trimethyl ammonium halide resulting. The (3-carbalkoxy-2-oxopropyl)-trimethyl ammonium is hydrogenated without isolating said halide from solution, a carnitine ester resulting. The carnitine ester is converted by means of aqueous hydrochloric acid into carnitine hydrochloride.