In Switzerland, mothers' involvement in paid work often occurs on a part-time basis. The mechanisms driving the decisions and opportunities to access part-time employment differ between native and immigrant populations. In this paper, we address the extent to which the employment behaviours of the female population differ by birthplace and family situation. Using data from the Swiss Labour Force Survey, we decompose the effect of human capital and household income on participation and the number of hours worked. Contrasting patterns of employment emerge among women born in Switzerland, within the EU, and outside the EU, especially in the presence of resident children. Women's education has a stronger positive effect on participation for natives, whereas household income is proved to have greater influence on the participation outcomes for the foreign-born population. Nevertheless, compared with immigrant women having the same level of education and household income, natives work the fewest number of hours.