We study the causal effect of motherhood on labour market outcomes in Latin America by adopting an event study approach around the birth of the first child based on panel data from national household surveys for Chile, Mexico, Peru, and Uruguay. Our main contributions are: (i) providing new and comparable evidence on the effects of motherhood on labour outcomes in developing countries; (ii) exploring the possible mechanisms driving these outcomes; (iii) discussing the potential links between these outcomes and the prevailing gender norms and family policies in the region. We find that motherhood reduces women’s labour supply in the extensive and intensive margins and influences female occupational structure towards flexible occupations—part-time work, self-employment, and informal jobs—needed for family–work balance. Furthermore, countries with more conservative gender norms and less generous family policies are associated with larger differences between mothers’ and non-mothers’ labour market outcomes.