Background: Dysfunctional trauma-related cognitions correlate highly with chronic stress. Studies on maltreatment-related cognitions and their predictors in children and adolescents are rare. Methods: The study sample consisted of 231 children aged 8-17 years who had experienced maltreatment including domestic violence, emotional abuse, neglect, physical, and sexual abuse. Using multiple linear regression analysis, gender, age, index-event, multi-type maltreatment, out-of-home-care, and migration background were investigated as possible predictors of dysfunctional maltreatment-related cognitions. Additionally, the associations between dysfunctional cognitions and posttraumatic stress symptoms (PTSS) as well as further internalizing and externalizing symptoms were calculated. Results: Gender emerged as a significant predictor of dysfunctional maltreatment-related cognitions. Moreover, there was an interaction effect of gender and age, with female adolescents showing most dysfunctional cognitions. Furthermore, experiencing five different maltreatment types had an impact, leading to more dysfunctional cognitions compared to single-type maltreatment. Dysfunctional maltreatment-related cognitions correlated highly with PTSS and internalizing symptoms, and moderately with externalizing symptoms. Conclusions: Dysfunctional maltreatment-related cognitions are associated with psychological symptoms after maltreatment and, therefore, need to be addressed in assessment and treatment.