ABSTRACT In Sweden, young people with behaviours considered norm-breaking and destructive by society are placed in secure institutional care. While these young people’s behaviour is frequently debated, there is little knowledge about their family and home conditions. This study aims to identify writings (i.e. wordings, sentences, etc.) referring to Adverse Childhood Experiences (ACEs) in child welfare assessments of a sample (n = 84) of young people placed in secure institutional care. The documentation was analysed by applying manifest quantitative content analysis using ACEs established in previous research as deductive categories. In addition, wordings related to the legal grounds for placement were also identified. The analysis shows that the burden of child abuse and household dysfunction is large in the sample. Compared to population-based prevalence studies, the current study presents much higher numbers, with almost 90% of the cases containing writings with reference to at least one ACE category and 38–50% referring to four or more. The findings constitute an important contribution to research on young people in secure care, by adding knowledge about adversity during childhood as a crucial part of these young people’s needs and challenges.