It is well documented that women have generally higher morbidity rates than men. In line with this women are also more absent from work due to sickness. This paper considers one popular explanation of the morbidity difference in general and of the difference in sickness absence in particular, viz. that women to a greater extent than men are exposed to the 'double burden' of combining paid work with family obligations. We discuss theories of role overload and role conflict, which both assume that the combination of multiple roles may have negative health effects, as well theories of role enhancement, which assume positive health effects of multiple roles. Using two large Norwegian data sets, the relationship between the number of and the age of children on the one hand and sickness absence on the other is examined separately for men and women and for a number of theoretically interesting subpopulations of women defined in terms of marital status (also taking account of unmarried cohabitation), level of education, and working hours. Generally speaking the association between children and sickness absence is weak, particularly for married people of both genders. To the extent that married persons with children are more absent than married persons without children, this is largely due to respiratory conditions. The relationship between children and sickness absence is somewhat stronger for single, never married mothers, but not for single mothers who have been previously married or for women living in unmarried cohabitation. The findings thus provide little support for either role overload/conflict or role enhancement theories. The possibility that these effects are both present and counterbalancing each other or that they are confounded with uncontrolled selection effects can not, however, be ruled out.