Using the theoretical and methodological framework of C.S. Peirce’s theory of signs, the author moves from the assumption that translation is a special form of sign–action or semiosis. Simply stated, this means that all translating is semiosis but not all semiosis is translating. The author tries to show that semiotics is good for Translation Studies for (at least) five reasons: (1) it is a theory of signs in general, not of verbal language; (2) it provides a viable model for the core of translation events; (3) it redefines the traditional image of translating as transfer; (4) it casts new light on equivalence and loss; and (5) it affords an investigation of the logico-semiotic conditions to translation in general. The last point is crucial. Three existential characters can be identified for translation semiosis: difference, similarity, and mediation. Together, they can help us frame a fundamental question: 'What do we talk about when we talk about translation?'