The current study examined whether differences in commitment to paid employment or different levels of private sphere responsibility between women and men could explain the gender segmentation of the paid work force. A survey of a composite sample (N= 380) of Australian nurses showed that there were no significant differences between women and men in terms of commitment to paid employment although commitment was a predictor of seniority. Primary care-giving status also predicted seniority and women were more likely than men to have care-giving responsibility for dependents. Multiple logistic regression showed that, independent of gender, primary responsibility for care-giving to dependents, rather than commitment to paid employment, explained more of the differing chances for women and men of being in senior positions.