Ten sleep-maintenance insomniacs and 11 good sleepers were issued electronic pagers. They activated their devices during their waking hours and completed the Marchini Monitoring Inventory (MMI) when paged at random intervals throughout the day. The insomniacs spent significantly more time shopping, watching television, and relaxing, whereas good sleepers spent significantly more time talking to people, working, and studying. Good sleepers thought more about their day's routine, everyday problems, work, and their interpersonal relationships with family members; insomniacs thought more about their immediate physical environment and numerous forms of passive relaxation. Good sleepers appeared busier, more active, and more involved in their work and with other people. Insomniacs seemed more preoccupied with self. Insomniacs might benefit from treatment strategies that entail increased activity and involvement with other persons and external events.