This paper discusses the fronting of a focal constituent to a clause-initial position which, in various languages, is associated with an import of unexpectedness. We provide prosodic and syntactic evidence from Italian showing that this phenomenon has distinctive grammatical properties with respect to other instances of “focus fronting”. We argue that the fronted constituent bears narrow focus, and that the unexpectedness import conveys that the asserted proposition is less likely than one or more distinct focus alternatives (see Grosz 2011). We characterize this import as a conventional implicature, and we argue that likelihood is interpreted with respect to an informative modal base which is shared by the conversational community (the context set). We show that the unexpectedness import expressed by a speaker can be accepted or rejected by the other discourse participants: thus, it qualifies as an evaluative commitment of the speaker and, when accepted by the interlocutors, it can give rise to a shared evaluation.