The aim of this study was to investigate professionals’ views on the proposal to replace secure youth care with youth detention for young offenders aged 13–17. The proposal for youth prisons has raised questions about how Swedish society should deal with young people who commit serious crimes, particularly in relation to the best interests of the child, the protection of society and social reintegration. The study was conducted as a qualitative interview study using semi-structured interviews, in which six professionals with varying experiences of working with young offenders were interviewed. The collected data was subsequently analysed using thematic analysis. The analysis was based on labelling theory, social control theory and professional vision theory, with the aim of investigating how professionals' reason about youth detention and what possible consequences they believe the sanction may have. The results show that professionals describe youth detention from several different perspectives. A central theme concerns youth detention as a social marker, as several interviewees highlight the risk of labelling and the reinforcement of a criminal identity. Furthermore, several interviewees argue that youth detention risks reinforcing a criminal identity among young people, which may hinder their reintegration into society. Another theme concerns the fact that youth detention can be seen both as a risk and as a possible sanction. Several risks are highlighted, such as the possibility that young people may be negatively influenced by others and that their schooling may be hindered. At the same time, some interviewees believe that youth detention can have certain advantages, such as providing a clearer consequence, greater control, and acting as a deterrent to further criminality.