Background <p>In individuals with substance use disorders (SUDs), impairment of social, occupational, and/or recreational functioning is common. Social functioning encompasses social skills, social behavior, and cognitive skills, which are relevant for establishing meaningful relationships and effective functioning across different domains in life. The main aim of the study is to determine the effectiveness of tailored virtual reality (VR) social functioning training as an adjunct to in-patient SUD treatment in improving functionality, measured by World Health Organization Disability Assessment Scale 2.0 at 6&#xa0;months post-intervention.</p> Methods <p>The study is designed as a two-arm, statistician-blinded, pragmatic, multi-cite, randomized controlled trial. Eligible participants will be randomly assigned to either the intervention or control group using 1:1 allocation. The control group receives standard in-patient SUD treatment, and the intervention group receives additionally VR social functioning training (8 sessions). Both the intervention and control groups will be assessed for between-group differences in functioning change from before randomization (T0), to 6-week (T1), and to 6-month (T2). Both groups will also be assessed before (T0), at 6-month (T2), and at 12-month follow-up (T3) for a health economic evaluation.</p> Discussion <p>Evidence suggests that VR training can enhance patients’ social functioning and thereby improve relations and promote community participation in people with SUD. To the best of our knowledge, this is the first study that aim to explore the use of VR in improving social functioning in patients with SUD. Thus the results of this trial can provide valuable insights for clinicians and health authorities.</p> Trial registration <p>ClinicalTrials.gov NCT06677515. Registered on November 11, 2024.</p>