BACKGROUND: Sleep disturbance has been described in bipolar disorder (BPD). Specific complaints may include frequent nighttime awakenings, poor quality of sleep, reduction in total sleep time, and nightmares. Most patients with BPD also report insomnia when in depression, but a significant percentage of patients report hypersomnia symptoms with prolonged nighttime sleep, difficulty in wakening, and excessive daytime sleepiness. OBJECTIVES: The present study aims to investigate whether bipolar patients with sleep disorders presented impairment in quality of life, disability, and global function. METHODS: One hundred ninety bipolar patients type-I diagnosed by application of Structured Clinician Interview for DSM-IV Disorders (SCID), were distributed in two groups based on absence or presence of sleep disorders. Quality of life, disability, and global dysfunction were evaluated using the Health Organization's Quality of Life instrument (WHOQOL-Brief), the Sheehan Disability Scale, and the Global Assessment of Functioning (GAF), respectively. RESULTS: Sleep complaints have negative influence on general quality of life, observed by decreased scores in WHOQOL and GAF domains and increased Sheehan scores, indicating the importance of maintenance of normal sleep in bipolar patients. CONCLUSION: Our results suggest that sleep complains impair quality of life and global function. Collectively, further studies are warranted to investigate the impairment of sleep disturbance on others neurotrophic factors and neurochemical pathways.