The study of the religious life of craftsmen in ancient Greece is progressively revealing the great complexity of the beliefs about the productive process and the related practices. Among the questions raised by these first results, it is very interesting to focus our attention on the way to represent gods and others characters related to crafts. Indeed, the religious representations discovered in workshops are mostly characterized by unrefined, «daemonic» aspects, both in the iconography and in the technical realization. At the same time, with regard to the official pantheon, it is surprising to notice that the only god who presents physical deformations is Hephaestus, the god of the smiths. The aim of this contribution is to review the iconographic data and to interpret them in the context of real cult practices.