International teaching assistants (ITAs) have a prominent role in the internationalisation of higher education (IHE). Although ITAs are considered important actors in IHE and ITA programs have a relatively long history, there is a scarcity of review studies on empirical research focusing on ITAs. This qualitative metasynthesis explores the research foci, methods and main findings from twenty-nine studies focusing on ITAs in higher education contexts. Based on template analysis, four main categories emerged. These were: ITA perspectives, student perspectives, TA perspectives and instructional interactions. Key issues include foreignness and differences in linguistic, cultural and educational backgrounds of ITAs. This metasynthesis highlights the need for institutions to acknowledge ITAs' unique transcultural characteristics and integrate reflexivity into programs to develop awareness among individuals, thereby reducing superficial biases.