The chapter focuses on the metacognitive model of generalized anxiety disorder (GAD) and describes the structure, choice, and implementation of treatment strategies in metacognitive therapy (MCT). Difficult to control worry is the central feature of GAD. Worry is a predominantly verbal conceptual process involving chains of negative thoughts. The majority of psychotherapy outcome research conducted on GAD has focused on interventions that fall under the rubric of cognitive-behavioral therapy (CBT). A considerable number of meta-analytic reviews and over 30 clinical trials have resulted in clinical guidelines recommending CBT as a first line treatment for GAD. Adrian Wells advanced a metacognitive model and treatment of GAD with the aim of improving therapeutic outcomes. Metacognitive therapy aims to modify negative beliefs about the uncontrollability and danger of worrying, and provide the patient with alternative nonconceptually based strategies for reacting to negative thoughts.