Therapists delivering trauma-focused interventions are at risk of developing conditions such as secondary traumatic stress or post-traumatic stress disorder. SCTherapist, an online guided self-help intervention designed to reduce symptoms of PTSD and improve self-compassion, was developed to address a current intervention gap for trauma therapists. The present study employed a single case experimental design to assess the effectiveness of the SCTherapist intervention using a sample of six trauma therapists. Symptoms of post-traumatic stress disorder and self-compassion were both assessed at baseline, post-intervention and three-month follow-up. Daily questionnaire data assessing distress, emotional distance and self-compassion were collected. One participant’s self-compassion scores improved significantly in daily self-report data. All other daily data did not show significant changes. Five participants improved in overall post-traumatic stress disorder scores between baseline and post-intervention, and three maintained improvements at follow-up. Self-compassion scores improved for five participants post-intervention and four participants reported improvements at follow-up. The intervention was found to be acceptable to participants. Implications and areas for future research are discussed.