Emerging conceptualizations of major emotional disorders emphasize their commonalities rather than their differences, including considerable overlap in disorder phenomenology, a common set of vulnerabilities to development of emotional disorders, and generalization of treatment response across disorders. Current research lends support for a unified transdiagnostic approach to treatment of these disorders that considers these commonalities and is applicable to a range of emotional disorders. Unified Protocol for Transdiagnostic Treatment of Emotional Disorders, part of the Treatments That Work series of therapist manuals and patient workbooks, is a radical departure from disorder-specific treatments of various emotional disorders, and is designed to be applicable to all anxiety and unipolar mood disorders, as well as other disorders with strong emotional components, such as many somatoform and dissociative disorders. The Unified Protocol (UP) capitalizes on the contributions made by cognitive-behavioral theorists by distilling and incorporating the common principles of CBT present in all evidenced based protocols for specific emotional disorders, as well as drawing on the field of emotion science for insights into deficits in emotion regulation. The UP contains seven modules and focuses on four core strategies: becoming mindfully aware of emotional experience; reappraising rigid emotion laden attributions; identifying and preventing behavioral and emotional avoidance; and facilatating exposure to both interoceptive and situational cues associated with emotional experiences. Unified Protocol for Transdiagnostic Treatment of Emotional Disorders will be an essential resource for all therapists and psychiatrists who implement CBT strategies, as well as any clinician treating anxiety and depressive disorders.