An increasing number of mothers with young children are in paid employment and the effect of this on family life is of increasing policy and scientific interest. Based on the first wave of the Longitudinal Study of Australian Children, this paper investigates potential sources of work-to-family strain for partnered parents of young children. The analysis identifies the importance of gender, job characteristics such as flexibility and autonomy, non-standard hours and long work hours, and the nature of the family environment - parental roles, supportive husband wife relationship - in exploring how working parents experience negative spillover between their work and family lives.