Biological invasions are one of the main threats to biodiversity, impacting local communities in multiple ways. In particular, their trophic impacts can be manifold, due to the novel trophic relationships arisen. Stable isotopes analysis (SIA) of carbon and nitrogen is increasingly used to investigate such relationships, by reconstructing the diet of non-native species in the introduction areas and, subsequently, the potential predatory impact on native preys. SIA also allows to quantitatively estimate the trophic position and the trophic niche breadth, which have shown interesting intraspecific patterns between native and non-native populations. Moreover, SIA can be used to estimate the overlap of the trophic niches between native and non-native species, thus assessing their potential feeding competition. Other trophic interactions can be also studied using SIA in invaded communities, such as the trophic competition between non-native species and the role of non-native species in the (altered) trophic web. Finally, recent studies have proposed a predictive approach, using SIA data to model the potential competitive and predatory im-pacts of non-native species on the recipient communities.