Objective: The purpose of this study was to assess the effectiveness of a new manualized group Meta-Cognitive Therapy (MCT) for adults with ADHD that extends the principles and practices of cognitive-behavioral therapy to the development of executive self-management skills. Method: Thirty adults diagnosed with ADHD completed an 8- or 12-week program designed to target impairments in time management, organization, and planning skills. Treatment efficacy was measured using pre- and posttreatment self-report standardized measures (CAARS-S:L & Brown ADD Scales). Results: General linear modeling revealed a robust significant posttreatment decline on the CAARS "DSM-IV" Inattentive symptom scale (p less than 0.001) as well as improvement on the Brown ADD Scales (p less than 0.001). Conclusion: The findings indicate that participants in the MCT program showed marked improvement with respect to core ADHD symptoms of inattention, as well as executive functioning skills, suggesting that this program has promise as a treatment for meta-cognitive deficits in adults with ADHD.