Using data from the UK's Third Work-Life Balance Employee Survey (2006) this paper explores whether long working hours, characteristic of British fathers, is best explained by men's career stage or their parental status. Guided by theoretical concepts "father as breadwinner" and "father as carer," it is hypothesised that fathers will work long hours to fulfil an economic provider role and "caring fathers" will work less hours to be more involved in the family. Men without dependent children are assumed to have lesser economic and caring demands or motivations. Regression models showed that being a father, rather than career stage, predicted working longer hours, controlling for earnings, education and partner's work status. However, being in a professional occupation predicted working longer hours for all men, irrespective of parental status.