The invention relates to a process for preparing a salt of an optionally substituted 4-benzimidazol-2-ylmethylamino)-benzamidine, characterised in that (a) an optionally correspondingly substituted diaminobenzene is condensed with 2-[4-(1,2,4-oxadiazol-5-on-3-yl)-phenylamino]-acetic acid, b) i) the product thus obtained is hydrogenated, ii) optionally the amidino group is carbonylated, without isolating the intermediate product of the hydrogenation beforehand and iii) without prior isolation of the intermediate product of the carbonylation the desired salt is isolated.