Witnessing violence toward a caregiver during childhood is associated with negative impact on children's health and development, and there is a need for effective interventions for children exposed to intimate partner violence in clinical as well as in community settings. The current effectiveness study investigated symptom reduction after participation in two established group interventions (one community-based psychoeducative intervention; one psychotherapeutic treatment intervention) for children exposed to intimate partner violence and for their non-offending parent. The study included 50 children—24 girls and 26 boys—aged 4–13 years and their mothers. Child and maternal mental health problems and trauma symptoms were assessed pre- and post-treatment. The results indicate that although children showed benefits from both interventions, symptom reduction was larger in the psychotherapeutic intervention, and children with initially high levels of trauma symptoms benefited the most. Despite these improvements, a majority of the children's mothers still reported child trauma symptoms at clinical levels post-treatment. Both interventions substantially reduced maternal post-traumatic stress. The results indicate a need for routine follow-up of children's symptoms after interventions.