Mentalization-based treatment (MBT) has gained international acclaim as an efficient treatment for patients with borderline personality disorder. The approach is also helpful for other personality disorders and conditions that are difficult to treat, e.g. addiction and eating disorders. MBT consists of a psychoeducational, an individual, and a group therapy component. This is the first comprehensive manual for mentalization-based group therapy. The author has developed the manual in close cooperation with Anthony Bateman and a team of group analysts. It covers all the aspects of MBT which are necessary to produce an informed and qualified group therapist. The book covers the theory behind mentalization and borderline personality disorder (especially its evolutionary roots), the structure of MBT and a discussion of previous experiences with group psychotherapy for borderline patients. The core of the book explains the main principles of MBT-G and provides a powerful means for ensuring that therapists adhere to these principles in a qualified way. The last part contains a full transcript from a real MBT group composed of borderline patients. As the first book dedicated to Group MBT, this book is a valuable and unique addition to the Mentalization literature.