The invention describes an improved process for the synthesis of duloxetine and/or pharmaceutically acceptable salts thereof enabling preparation of duloxetine and/or pharmaceutically acceptable salts thereof with high chemical and enatiomeric purity. The process includes addition of an organic acid in the phase of formation of a duloxetine salt with an acid, preferably in the form of hydrochloride, and optionally in the phase of recrystallization of the formed duloxetine salt, wherein an organic acid is preferably selected from the group comprising formic acid, acetic acid, propanoic acid, butanoic acid or any mixtures thereof, more preferably acetic acid.
