The device for printing endorsements on documents is desig­ned for mounting on processing equipment for certain types of documents - for example bank documents - so that once such documents have been printed and/or read by the processing equipment, they can be endorsed. For this purpose the device invented carries a stamp (8) and whatever numbers or characters are required, all mounted upon a revolving cylindrical body (1) which will press against the required documents as it turns; moreover, the same turning movement will serve to ink the stamp (8) and characters as these brush against an ink roller (10) located beside and at a tangent to the cylinder body (1); and finally, the device is normally in a blocked position, held by a flange (17) which can be released by means of an electromagnet (16).