For some time now, quality of life has been an important criterion of the success or failure of medical treatment, especially in sleep medicine. Sleep disorders have an effect not only on sleep quality, but also on the state of mind and the state of health during the day. The latter, in turn, is an important parameter of subjectively perceived quality of life. The aim of this study was to investigate the influence of the different sleep disorders (insomnia, narcolepsy, obstructive sleep apnea syndrome) on the quality of life. For this study, 100 patients with sleep disorders with clinical pictures as listed and 40 controls were given questionnaires to gather data both on sleep quality and quality of life. For global life quality as well as specific areas, distinct differences were found between the patient groups both among each other and healthy persons, whereat healthy persons mostly showing the highest life quality. Further research in this area, especially during the course of therapy, is thus called for, as findings can be expected to provide a basis for important insights.