<p>Process for crystallising Bupropion hydrochloride comprising the following stages: a) Bupropion hydrochloride is dissolved in a mixture comprising methanol and a precipitating solvent for Bupropion hydrochloride; b) any insoluble residue is removed; c) the solution is distilled at atmospheric pressure until the precipitation reaction is triggered; d) the following are added: I) a precipitating solvent for Bupropion hydrochloride and II) hydrochloric acid until a pH <= 2 is obtained; e) the mass is cooled to a temperature less than 10° C, preferably between 0 and 3° C and the precipitate obtained is separated.</p>