Self-reported sleep quality, strain and health in relation to perceived working conditions in females The aims of this study were to examine self-reported sleep quality, perceived strain and health in relation to working conditions; the prevalence and severity of sleep disturbances and daytime distress arising from poor sleep in women on different work shifts. Furthermore, to see whether females with gastrointestinal symptoms, joint-, back- or muscle-pain and who are dissatisfied with working hours differ with regard to the above aspects. Finally, degree of strain-related symptoms and sleep difficulties were tested as predictors of sleep quality and general health outcome. Important research questions are whether registered nurses and those on rotating work shifts have greater sleep problems than others. A total of 156 females, aged 20-59 years, working at three different casualty departments, answered structured questionnaires. The results showed a persistently high rate of psycho-physiological long-term effects of stress related to working conditions. Thirty-four per cent were dissatisfied with their working hours, and exhibited significantly more mental strain, fatigue/excessive tiredness and inability to relax after work because of involuntary thoughts, in relation to working conditions than others did. Sixty-two females (39.7%) complained of insufficient sleep. The sleep quality outcome was significantly predicted by difficulty falling asleep (odds ratio 8.4), difficulty in falling asleep after nocturnal awakening (odds ratio 3.4) and perceived exhaustion (odds ratio 2.6). Females suffering from gastrointestinal symptoms and joint-, back- and muscle symptoms for several days in a week or even everyday were especially sensitive to worse sleep quality. Independent of work shifts, registered nurses exhibited a higher degree of mental strain and prolonged recovery in comparison with others. In conclusions, sleep initiation difficulties, troubled sleep and exhaustion significantly predicted reduced sleep quality outcome with decreased resilience to stress and vulnerability to psycho-physiological disorders in females working within the health care system.