The scientific study of compassion, and its application to clinical problems, has been growing rapidly in the last ten years. Compassion focused therapy (CFT) was specifically developed with and for people with mental health difficulties. This chapter offers a scoping review of the growing body of process and outcome studies on this therapy. The chapter covers both a variety of mental health difficulties and also studies in non-clinical populations. The review highlights the encouraging emerging data on the effectiveness of this therapy for a wide range of difficulties.