The primary aim of this equivalence study was to compare the outcome of a brief group therapeutic intervention, based on the principles of dynamic interpersonal therapy (DIT) with an intervention based on cognitive behavioural therapy (CBT) in patients suffering from medically unexplained somatic symptoms (MUSS). Participants were 89 patients (aged 18 to 62) who were offered 20 sessions of either DIT or CBT, as central part of a treatment package, consisting of art therapy, psychomotor therapy, social therapy and physical therapy. Measurements were conducted at baseline, 10 weeks and 20 weeks, using self-rating scales measuring the level of anxiety and depression, the severity of medically unexplained symptoms and quality of life. Results showed that CBT and DIT were comparable. The conclusion was that it is recommended to design a larger scale randomised controlled trial to further elaborate the short-term and long-term effects of this novel psychodynamic group therapy for MUSS patients.