Background: Bipolar disorder (BD) is commonly associated with cognitive and functional impairments even during remission periods, and although a growing number of studies have demonstrated the benefits of psychotherapy as an add-on to pharmacological treatment, its effectiveness appears to be less compelling in severe presentations of the disorder. New interventions have attempted to improve cognitive functioning in BD patients, but results have been mixed. Methods: The study consists of a clinical trial comparing a new structured group intervention, called "CognitiveBehavioral Rehabilitation,"with treatment as usual (TAU) for bipolar patients. The new approach is a combination of cognitive behavioral strategies and cognitive remediation exercises, consisting of 12 weekly group sessions of 90 min each. To be included in the study, patients must be diagnosed with BD type I or II, aged 18-55 years, in full or partial remission, and have an IQ of at least 80. A comprehensive neuropsychological battery, followed by mood, social functioning, and quality of life assessments will occur in three moments: pre and post intervention and 12 months later. The primary outcome of the study is to compare the time, in weeks, that the first full mood episode appears in patients who participated in either group of the study. Secondary outcome will include improvement in cognitive functions. Discussion: This is the first controlled trial assessing the validity and effectiveness of the new "Cognitive-Behavioral Rehabilitation"intervention in preventing new mood episodes and improving cognitive and functional impairments.