Background: Selling sex is not uncommon among adolescents and we need to increase our knowledge of how this affects them. Aim: The aim of this study was to investigate adolescents who sell sex regarding sexual, mental and physical abuse, mental health as estimated by using the Hopkins Symptom Check List-25 (HSCL-25), self-harm behaviour and the adolescents’ experience of receiving help and support. Methods: The study was carried out on a national representative sample of adolescents (mean age 18.3 years) in Swedish high schools in the final year of their 3-year programme. The study had 3498 participants and a response rate of 60.4%. Results: Of the adolescents, 1.5% stated that they had sold sexual services. The selling of sex was associated with a history of sexual, mental and physical abuse. Poorer mental health and a higher degree of self-harm behaviour were reported among the adolescents who had sold sex. Help and support was sought to a greater extent by adolescents who had sold sex but these adolescents were not as satisfied with this help and support as the other adolescents. Conclusions: Adolescents that sell sex are a group especially exposed to sexual, mental and physical abuse. They have poorer mental health and engage in more self-harm behaviour than other adolescents. They are in need of more help and support than other adolescents and it is reasonable to assert that more resources, research and attention should be directed to this group to provide better help and support in the future.