INTRODUCTION: Social Anxiety Disorder (SAD) is a highly prevalent and debilitating disorder. While effective treatments exist, they are not always easily accessible or helpful for all patients. This highlights the need for accessible treatment alternatives. The aim of the STePS study was to evaluate internet-delivered psychodynamic therapy (IPDT) with and without therapist support, compared to a waitlist control condition, in the treatment of adults with SAD. METHODS: In this randomized clinical trial, we tested whether IPDT was superior to a waitlist control, and whether IPDT with therapeutic guidance was superior to unguided IPDT. Participants were recruited nationwide in Sweden. Eligible participants were ≥ 18 years old, scoring ≥ 60 on the Liebowitz Social Anxiety Scale self-report (LSAS-SR) without meeting any exclusion criteria. Included participants were randomly assigned to IPDT with guidance (n=60), IPDT without guidance (n=61), or waitlist (n=60). The IPDT intervention comprised eight self-help modules based on affect-focused dynamic therapy, delivered over 8 weeks on a secure online platform. The primary outcome was SAD symptom severity measured weekly by the LSAS-SR. Primary analyses were conducted on an intention-to-treat sample, including all randomly assigned participants. Secondary outcomes included depressive symptoms, generalized anxiety, quality of life, emotion regulation, and defensive functioning. RESULTS: During the conference, results obtained from the study at post-treatment, as well as at 6- and 12-month follow-ups will be presented. CONCLUSION: This is the second RCT to investigate the efficacy of IPDT in the treatment of SAD. If found efficacious, IPDT should be compared to existing evidence-based internet-delivered treatments.