Little is known about whether and how to treat mental images of childhood ritualistic sexual and physical abuse, which may include bizarre elements. Patients experiencing disturbing mental images of childhood ritualistic abuse pose a significant clinical challenge due to the lack of clear treatment guidelines. To advance the understanding of therapeutic options for such complex cases, we present a case study of a highly fantasy-prone middle-aged woman experiencing intrusive images of bizarre ritual abuse, which were treated using Imagery Rescripting (ImRs). These images had not been successfully addressed in previous treatments. The patient underwent 14 sessions of ImRs, during which symptoms of posttraumatic stress disorder (PTSD; assessed with the PCL-5), emotional tolerance, mastery over the images, and feelings of guilt were monitored. Pre- and post-treatment assessments included the CAPS-5 interview for PTSD. A semi-structured interview was conducted six months after treatment to assess the patient’s experience. Results showed a reliable reduction in PTSD symptoms, increased control over the images, improved emotional tolerance, and decreased guilt. No adverse effects, such as the creation of new images, were observed. We discuss the implications of these findings in the context of current knowledge about the treatment of childhood ritual abuse-related imagery, explore clinical principles, and offer recommendations for further implementation.