Taking into account interdependence within the family, we investigate the relationship between part-time work and family wellbeing. We use panel data from the Household, Income and Labor Dynamics in Australia (HILDA) Survey. We find that part-time women are more satisfied with working hours than full-time women, and that women's life satisfaction is increased if their partners work full-time. Male partners' life satisfaction is unaffected by their partners' market hours but is increased if they themselves are working full-time. Our results are consistent with the gender identity hypothesis.