Abstract A sizeable body of literature has shown that the migrant-native employment gap is larger among women with children than among childless women, suggesting that the transition to parenthood has a stronger impact on the employment trajectories of migrant origin women compared to those of native women. However, due to the limited use of longitudinal data, our understanding of the mechanisms generating differential employment trajectories around the transition to parenthood remains limited. This study adopts a life course perspective to address path-dependencies in employment trajectories around the transition to motherhood. Using longitudinal data and fixed-effects models that compare within-individual changes in contractual working hours around the transition to parenthood between natives and second-generation migrants of Southern European and Turkish or Moroccan origin in Belgium, we find no migrant-native differentials among women with low employment rates before the birth of their first child and only limited differentials in employment trajectories around parenthood among women with medium and high employment rates before parenthood. This indicates that there is a strong path-dependency of employment trajectories around parenthood for migrant women and natives alike, but that second-generation migrant women generally have a lower pre-birth labour market attachment than native women which accounts for the frequently observed migrant-native differentials in maternal employment.