Already since antiquity the knocker, as a secondary usable and decorative element of the door, must have expressed aspects of a mystical, cosmological and religious thought. The assimilative power of folk civilization, in spite of the radical historical, religious and social realignments, has not only conserved, but it has also en¬riched its morphoplastic vocabulary, preserving at the same time a palimpsest of beliefs and superstitions that refer to the house doors and gates. The present research and study of the modern folk knockers has a double objective: on the one hand, through an original typological classification, to set off the wealth of their form elaboration; and on the other, to project the sym¬bolism and beliefs that they probably include. In our days the knockers gradually vanish from house doors. At the same time their modern form expressions for purely decorative functions seem to be inferior to the artistic aesthetic and their symbolism, and thus they are degraded in industrialized forms, which copy the most popular old models. Although quite many modern urban and folk knockers still survive, a great part of this urban heritage is lost forever. Their concise study attempts to recall and to compose memories and pictures of our youth.