Background: Conduct disorder (CD) is a complex mental disorder characterized by severe rule breaking and aggressive behaviour. While studies have shown that several therapeutic interventions are effective in treating CD symptoms, researchers call for treatments based on etiological knowledge and potential patho-mechanisms. Mentalization-based treatment (MBT) may represent such a treatment approach: Studies have shown that individuals with CD show mentalizing deficits and that mentalizing might represent a protective factor against the development of the disorder. As MBT focuses on the understanding of social behaviour in terms of mental states, fostering mentalizing might help CD individuals to (re)gain an adaptive way of coping with negative emotions especially in social interactions and thus reduce aggressive behaviour. For this purpose, MBT was adapted for adolescents with CD (MBT-CD). This is a protocol of a feasibility and pilot study primarily investigating the acceptability of the intervention and the scientific assessments by CD individuals and their families based on quantitative and qualitative data as well as necessary organizational resources. Secondary aim is to investigate the course of symptom severity and mentalizing skills.Methods: The bi-centre study is carried out in two outpatient settings associated with University Hospitals (Heidelberg and Mainz) in Germany. Adolescents aged between 11 and 18 years with a CD or oppositional defiant disorder (ODD) diagnosis are included. Participants receive MBT-CD for 6 to 12 months. Primary outcome of the feasibility study (e.g. recruitment and adherence rates) will be descriptively analysed. Multilevel modelling will be used to investigate secondary outcome data.Discussion: Fostering the capacity to mentalize social interactions triggering non-mentalized, aggressive behaviour might help CD individuals to behave more adaptively. The feasibility trial is essential for gathering information on how to properly conduct MBT-CD including appropriate scientific assessments in this patient group, in order to subsequently investigate the effectiveness of MBT-CD in an RCT.