Aims: The aim of this study is to analyse how increasing demands from work and family life affect the level of strain and whether there are any significant gender differences in this respect. This is be done by testing the following hypotheses: An increase in work and family demands causes (a) an increased risk of suffering from fatigue; (b) an increased need for working fewer hours. Methods: The hypotheses are analysed by using a longitudinal data set consisting of nearly 9,000 Swedish individuals. Results: Multiple demands increase the risk of suffering from fatigue among both women and men, but it is only among women that an increase in the percentage desiring a reduction in their working hours can be found. Conclusions: The results support the role stress theory, especially among women.