Summary Several European studies have reported sleeping problems in 20-40% of the population. We used data from the Population Study of Women in Gothenburg, based on medical examinations of three different representative cohorts of 38- and 50-year-old women in 1968-1969, 1980-1981 and 2004-2005 to study secular trends in sleep-related factors. The average reported sleep duration declined by about 15 min in the 38-year-old women during the 36 years of observation. No corresponding change in sleep duration was observed among 50-year-old women. During the same period, the proportion of women complaining of sleeping problems almost doubled in both age groups: from 17.7% in 1968 to 31.7% in 2004 in 38-year-old women, and from 21.6% to 41.8% in 50-year-old women. The prevalence of insomnia was higher in 50-year olds than in 38-year olds in all investigated cohorts. The use of sleeping medications remained unchanged since 1968. There were significant associations between perceived sleeping problems and reported lower satisfaction concerning economic, social and family situations, as well as with medical retirement and mental stress. There was, however, no association between alcohol consumption and sleeping problems. Regular leisure time physical activity was not, in most cases, associated with less perceived sleeping problems. Our study indicates that the physician should take socio-economic and family situations into consideration when examining female patients complaining of sleeping problems. Improvements on society level rather than on the individual level could be expected to be more efficient in improving women's sleep.