The relationship between childhood trauma and dissociative experiences is widely acknowledged. However, the association between emotion regulation difficulties (ERD), anxiety/depression and dissociation in adolescents and young adults with cumulative maltreatment (CM) remains unclear. The present study examined the role of ERD at both intrapersonal and interpersonal levels and anxiety/depression symptoms in the development of psychoform or somatoform dissociation in adolescents and young adults with CM. We assessed 58 participants with CM and 55 participants without childhood trauma history between the age of 12 and 22 years old. Participants completed self-reports of ERD, anxiety/depression, psychoform dissociation and somatoform dissociation. The results revealed that adolescents and young adults exposed to CM displayed high levels of psychoform and somatoform dissociation, ERD and anxiety/depression symptoms. It was also found that intrapersonal and interpersonal ERD predicted psychoform dissociation, whereas anxiety/depression predicted somatoform dissociation in adolescents and young adults with CM. Intrapersonal and interpersonal ERD and anxiety/depression are therapy targets for clinical interventions in adolescents and young adults with CM and dissociative symptoms.