Anxiety and mood disorders are common, chronic, costly, and characterized by high comorbidity. The development of cognitive behavioral approaches to treating anxiety and mood disorders has left us with highly efficacious treatments that are increasingly widely accepted. The proliferation of treatment manuals targeting single disorders, sometimes with trivial differences among them, leaves the mental health professional with no clear way to choose one manual over another and little chance of ever becoming familiar with most of them, let alone trained to competence in their delivery. Deepening understanding of the nature of emotional disorders reveals that commonalities in etiology and latent structures among these disorders supersedes differences. Based on empirical evidence from the domains of learning, emotional development and regulation, and cognitive science, we have distilled a set of psychological procedures that comprise a unified intervention for emotional disorders. The Unified Protocol (UP) is a transdiagnostic, emotion-focused cognitive behavioral treatment, which emphasizes the adaptive, functional nature of emotions, and seeks to identify and correct maladaptive attempts to regulate emotional experiences, thereby facilitating appropriate processing and extinction of excessive emotional responding to both internal (somatic) and external cues. The treatment components of the UP are briefly outlined. Theory and rationale supporting this new approach are described along with some preliminary evidence supporting its efficacy. Implications for the treatment of emotional disorders using the UP are discussed. Depression and Anxiety, 2010. © 2010 Wiley-Liss, Inc.