Vat dyes are made by condensing a 41:51-dichloroo 41:51-dibromo-11:81-naphthoylene-benz- or naphthimidazole or substitution product thereof with a 1-amino-anthraquinone in the presence of an acid-binding agent and heating the chlorine- or bromine-containing intermediate thus obtained in the presence of an acid amide which may be substituted at the nitrogen atom, such as acetamide, pyrrolidone, benzamide or phosphoric acid-tris-dimethylamide, and an acid-binding agent in the presence or absence of an organic liquid such as a -chloronaphthalene at temperatures from 150 DEG to 270 DEG C. Olive-green to green vat dyes are obtained.