To evaluate the long-term safety and efficacy of eszopiclone administered for 12 weeks in elderly subjects with primary chronic insomnia.Administration of eszopiclone 2 mg daily at bedtime for 12 weeks in elderly subjects with a diagnosis of primary chronic insomnia will be safe and well tolerated, improve subjective sleep measures, improve measures of Quality of Life and next day insomnia symptoms, and have no significant withdrawal central nervous system adverse events or rebound insomnia.