AbstractIrony is a mechanism that, at the same time, says and does not say. It is a case in which the speaker literally expresses a sense that is not what the speaker wants to communicate. It is a case of implicit echoic mention that conveys an attitude toward what is mentioned. Therefore, an utterance that, to be understood, needs contextual elements, meta-communicative elements and a mutual attribution of knowledge, intentions and affective states between speaker and hearer; the elaboration of which requires specific capacities – linguistics as well as cognitive – that allow to recognize the unsaid intentions of the speaker. Even if the ironic speaker expresses an attitude and, in doing this, s/he is ‘honest’ (s/he wants the hearer to recognize the falsehood or the irrelevance of the expressed proposition and to grasp the attitude towards it), most of the time, ironic expressions are sentences that are apparently false. To be able to distinguish between irony and lying, the hearer must determine that the ironic speaker wants the listener to disbelieve the statement, whereas the liar wants the listener to believe just what is said. Distinguishing between a false observation said with a misleading intent and an untrue sentence proffered/uttered with an ironic intent, requires a right attribution of a second-order belief, but it also requires the capacity ofepistemic vigilance, an ability that allows us to evaluate the accuracy of the content of the information provided by others, and to discriminate the reliability of the source of information. The complex abilities, required by irony elaboration, make irony learning during childhood particularly difficult. Acquisition of irony comprehension is more complex than any other form of non-literal speech and, during growth, it reaches its complete development later than many other complex linguistic aspects, only about at the age of ten-twelve. The article wants to show how difficulties of irony elaboration in children are linked not only to the full development of meta-representational abilities, but in addition and especially to the development of epistemic vigilance.