Adolescents involved in criminal proceedings are significantly more likely to re-offend than a similar population diverted away from criminal justice. Adolescents who use substances and offend are at higher risk of experiencing negative social, psychological and physical problems that often persist into adulthood. There is some evidence that brief interventions combined with appropriate psychoeducation may be effective in reducing adolescent substance use. Prospective two-armed, individually randomized internal pilot randomized controlled trial (RCT) with follow-up at 6months. Young people across three police forces-Kent, Cornwall and Sefton-arrested in possession of class B or C illicit substances were randomly allocated to receive the ReFrame intervention or business as usual. In total, 102 participants were eligible of whom 76 consented and 73 were followed up at 6months. Outcomes addressed offending behaviour, frequency of substance use, wellbeing and mental health. The study was conducted between February and December 2022. All progression criteria were met, 80% of those eligible consented, 96% adhered to their allocated treatment and 88% were followed up at the primary endpoint. The feasibility of conducting the pilot trial was a success and it will now proceed to a definitive RCT.