Art therapy (AT) shows promise in treating clients with posttraumatic stress disorder (PTSD), especially those who don't respond well to traditional treatments (more than 30 %). This case study aimed to explore the effects of Trauma-Focused Art Therapy (TFAT) on PTSD symptoms and establish its viability as a non-verbal therapy for trauma-related issues. A 10-week intervention and a 3-week follow-up phase were explored using a mixed method single case experimental design (SCED) aimed at integrated results. Bringing the two types of data together adds value and enables to understand the findings better. Quantitative data was collected with weekly questionnaires focused on severity of depression, resilience, self-esteem, mental health and self-expression and emotion regulation in art therapy. The PTSD Checklist for DSM-5 (PCL-5) was completed in week 1 and 10. Qualitative data was collected through interviews, the patient dossier, and artwork. The combined findings indicate a decrease in PTSD symptoms, reduced depression symptoms, enhanced emotional articulation, increased mental resilience, self-esteem, and positive mental health. The qualitative data support these results, and also add improved emotional connection, increased emotional acknowledgment, and enhanced self-compassion. Based on the combined results of this mixed method design we understand that the TFAT protocol led to a clinically significant reduction in PTSD symptoms and improved mental health, demonstrating effectiveness of AT for trauma in this case. This is the first study that tested the TFAT protocol in posttraumatic distress.