Primary insomnia (PI) is a prevalent form of sleep difficulty that impairs diurnal functioning, reduces quality of life and enhances health care utilization/costs for millions worldwide. Whereas the underlying pathophysiology of PI remains poorly understood, it is widely accepted that a host of cognitive and behavioral factors play important roles in perpetuating this condition. As such, a multi-factorial, cognitive-behavioral therapy (CBT) has emerged as a "treatment of choice" for managing the sleep/wake complaints of PI sufferers. This article considers the nature and relative merits of CBT for treating PI patients. In addition, this article reviews studies supporting the general efficacy and clinical effectiveness of CBT for treating PI complaints. Issues related to treatment implementation as well as factors that mediate patients' responses to CBT and predict treatment acceptance/outcome are also considered. Finally, remaining questions regarding CBT's application to PI are considered, and suggestions for future research are provided.