While internationally there is long-standing research activity on the effectiveness of language contacts (especially in the form of mobility stays) at tertiary level and a number of literature syntheses on this field have been published, research projects at the primary and secondary level are still comparatively rare and the results are often not published in peer-reviewed journals. This literature review compares and systematises these works, some of which have received little or no international attention. By analysing and systematizing the findings, the literature review primarily aims to identify what is known about the effectiveness of student exchanges at these lower levels of education and where there are research gaps and a need for future research.