From a mentalizing perspective, in attachment trauma an individual’s experience of adversity is compounded by the sense that they have to be able to bear that experience alone. An overwhelming experience cannot be calibrated and managed within an attachment relationship. Normally another mind provides the social referencing that enables an individual to frame and reframe a frightening and potentially overwhelming experience. In the absence of this, the person cannot process the experience, and further development of mentalizing is disrupted. This chapter describes MBT-Trauma Focused (MBT-TF) work, and it illustrates the three phases of treatment by presenting clinical examples. Intervention focuses on mentalizing, avoidance, mental and behavioral systems, managing anxiety and dissociation, and trauma memory processing. An MBT intervention for complex PTSD that uses psychoeducation, group intervention, exposure, and looking to the future is outlined, and is illustrated with clinical examples.