In this article, we present a cognitive-behavioral model and treatment of generalized anxiety disorder (GAD). In the first section, we review a model of GAD that includes four main components: intolerance of uncertainty, positive beliefs about worry, negative problem orientation, and cognitive avoidance. Next we present the GAD assessment tools used at our clinic, which include standardized interviews and self-report questionnaires of GAD symptoms and underlying cognitive-behavioral processes. We then provide a step-by-step description of a treatment that is based on the aforementioned model of GAD, and that has six core components: presentation of treatment rationale (learning to cope with uncertainty); worry awareness training; reevaluation of the usefulness of worrying; problem-solving training; cognitive exposure; and relapse prevention. Following the treatment description, we summarize the efficacy data from our completed randomized clinical trials, and present some preliminary findings from our ongoing trial comparing our treatment to applied relaxation and wait-list control. In the final section, we present an in-depth discussion of future directions for the study and treatment of GAD, with a focus on the approach-avoidance nature of GAD. Given the movement in the field favoring the expansion of cognitive-behavioral treatments, we also comment on the possible implications of the newest integrative therapies for our existing treatment.