Complex posttraumatic stress disorder (C-PTSD) and adverse childhood experiences (ACEs) pose health problems in the United States, and intergenerational relational trauma plays a role in the continuation and transmission of these issues. Advanced Integrative Therapy (AIT), a novel treatment, was used to treat a case of C-PTSD. The client’s chief concern was a flare-up of anxiety, relational distress, and fibromyalgia that occurred when they (chosen pronoun) accepted custody of their nephew. Over a span of nine 90-minute sessions, the clinician assessed progress using the PTSD Checklist for DSM-5 (PCL-5; Weathers et al., 2013) to measure PTSD symptoms; the International Trauma Questionnaire (ITQ; Cloitre et al., 2018), which measures C-PTSD symptoms according to the criteria of the World Health Organization (WHO) International Classification of Diseases, 11th revision (ICD-11); the Child-Parent Relationship Scale (CPRS; Pianta, 1992), which measures connection and conflict in the caregiver-child relationship; and the Subjective Units of Distress (SUD) scale (Wolpe, 1969), which rates the client’s current level of distress or discomfort. The clinician also used the self-report questionnaire Helpful Aspects of Therapy (HAT; Llewelyn et al., 1988) and the Change Interview (CI) method (Elliott et al., 2001) to measure client experience and perspective. After treatment with AIT, the client no longer met criteria for C-PTSD and showed dramatic improvement in intergenerational relationship satisfaction. In addition, there was a rapid reduction of hard to eradicate C-PTSD symptoms as well as reduction in the quantity and intensity of fibromyalgia induced pain. Use of AIT with caregivers could interrupt the transmission of intergenerational trauma thereby reducing or preventing ACEs by increasing emotional regulation and resilience.