The presence of alien fish in inland waters has the potential to disrupt the community structure of endemic fish. Mahalona Lake has a high level of endemicity, although there are now several threats one of which is the existence of alien fish in Mahalona Lake. The purpose of this study was to examine the risks of having alien fish in Mahalona Lake. The research was carried out between January and March of 2023. Gill nets with mesh sizes of 0.75, 1.0, 1.5, and 2.0 inches were used to collect fish samples. The Freshwater Fish Risk Assessment Model (FRAM) with a scoring system was used to conduct the risk assessment. Six invasive fish species obtained in Mahalona Lake were subjected to FRAM analysis. The sedentary risk and impact on introduced fish risk values revealed that three species had high invasive potential, namely Amphilopus trimaculatus, Channa striata, and Oreochromis niloticus, while the other three species had moderate risk values, namely Anabas testudineus, Barbonymous gonionotus, and Trichopodus trichopterus. Amphilopus trimaculatus is an alien fish with the highest risk value, while Trichopodus trichopterus is a fish with the lowest risk value.