Abstract: A process for the preparation of sulfur-containing N-benzyl-amino acids of the formula ##STR1## wherein X and Y, which may be identical to or different from each other, are each hydrogen or halogen;R.sub.1 is hydrogen or alkyl of 1 to 4 carbon atoms;R.sub.2 is hydrogen, alkyl of 1 to 3 carbon atoms, carboxy-lower alkyl or acyl;R.sub.3 is hydrogen or acyl; andn is 1 or 2;which comprises the steps of converting anthranilic acid or a halogenated anthranilic acid into the corresponding aldehyde, reacting the aldehyde with a compound of the formula ##STR2## wherein R.sub.1, R.sub.2 and n have the meanings previously defined, to form the corresponding Schiff's base, reducing the said Schiff's base, and recovering the reaction product.