This paper discusses occurrences of Italian sapere ‘know’ in mental state attributions (sa). Following the proposal of Tsohatzidis (2012) for ‘knows’, the hypothesis put forward is that sa, when used in mental state attributions, is lexically ambiguous between a factive and a non-factive sense: when sa is used in its factive sense, a sentence such as X sa che p ‘X sa that p’ entails p, whereas, when sa is used in its non-factive sense, a sentence having the same surface form does not entail p. This hypothesis seems to be confirmed by some tests traditionally used to ascertain cases of lexical ambiguity. Moreover, it will be shown that there are syntactic environments where only one of the two readings is allowed, which also seems to confirm the hypothesis that there are two sa, a factive one and a non-factive one, which select different structures. (Less)