The protected landscape of Savica is the most valuable and the only wetland area of the city of Zagreb. The protected landscape includes a small part of the old branch of the Sava River (Stara Savica) and 13 interconnected lakes created by the expansion of the old river branches. According to the biological classification, the lakes belong to eutrophic lakes and provide all conditions for the life and development of fish populations. The goal of the research was to investigate the qualitative and quantitative composition of the ichthyofauna of Lake Savica and at the same time to determine biodiversity indices, the representation of non-native species and to determine the representation of species according to trophic and ecological groups. Sampling was carried out at 11 previously determined locations, in area of the protected landscape of Savica (from May to October 2023). Sampling was carried out by electrofishing. Basic functions in Microsoft Excel and biodiversity indices (Simpson index, Shannon-Wiener index and Brillouin index) were used to analyze the ichthyofauna. A total of 20 species of fish were recorded, of which 7 are non-native. The obtained results were compared with the previous research of Lake Savica. Savica is inhabited by fish of the lowland type of stagnant waters, the species are generally opportunistic with a few species of sporting interest.