The present study evaluates a multifaceted cognitive-behavioral group treatment in a routine clinical setting. The program consists of directly sleep related strategies such as sleep education, sleep restriction, stimulus control, relaxation, and cognitive restructuring. Also included are techniques that target illness maintaining factors such as stress-management, problem solving skills, and increase of activities. Twenty-eight physician-referred outpatients with chronic primary insomnia according to DSM-III-R criteria attended 11 weekly therapy-sessions. Results were obtained on a subjective and objective level using a sleep diary, questionnaires, and polysomnography, respectively. Pre- and post-treatment comparisons indicated significant changes on all main sleep diary variables, i.e. total sleep time, sleep efficiency, number of awakenings, sleep onset latency and wake after sleep onset, as well as for the global subjective sleep quality. Maximum improvement was reached after the more directly sleep-related part of the program. In addition, the intervention helped patients to reduce the amount and frequency of sleeping aids over time and improved their daytime-functioning. Subjective therapeutic gains were maintained at 3- and 12-month follow-ups. No significant treatment effects could be obtained on polysomnographic measures, taking into account that the baseline values were already in the normative range. After the intervention the patients were able to give a more realistic evaluation of their sleep. These results suggest that a multicomponent psychological treatment is beneficial for the improvement of sleep quality on a subjective level.