ABSTRACT Temporary youth mobility includes stays whose motives may be educational (e.g. linguistic stays), related to work (e.g. internship or volunteering) or cultural (e.g. with the objective to discover new cultures such as backpacking trips). Such stays are becoming increasingly popular among young adults. The lack of statistical data usually prevents studying temporary youth mobility beyond the specific case of mobile university students. This article fills that gap by analysing a dataset that covers a large part of the 18–20 year old population in Switzerland. It measures the prevalence of temporary youth mobility and assesses its selectiveness – or inequalities – according to a wide range of factors related to the life course. Our study confirms some results of the literature: Young adults from privileged social backgrounds, students in higher education and women are more mobile than average. We identify additional factors such as young adults’ familial constellation, and their linguistic region. We also highlight the importance of a mobility capital (language skills, knowledge of other countries, etc.) that can be transmitted by parents (e.g. if they themselves were mobile temporarily) or accumulated by young adults themselves (e.g. their previous mobility experiences).