By studying mothers’ labour earnings trajectories in Sweden and West Germany, this cross-national study emphasises strengths and weaknesses in both countries’ social policy settings regarding the protection of mothers from the adverse effects of separation. Using extensive register data, our sample consists of women who gave birth between 1992 and 2014. The observation window ranges from one year before the first childbirth until ten years after. Utilising fixed-effects regression models, we estimate whether earnings trajectories differ between mothers who experience separation in the years after childbirth compared to mothers who remain partnered. Results show that separation is negatively linked to the earnings trajectories of first-time mothers in Sweden, whereas it is positively linked in West Germany. In Sweden, although the earnings of separated mothers lag behind those of partnered mothers, both groups can return to their pre-birth earnings levels. In West Germany, however, both partnered and separated mothers’ earnings remain far below pre-birth levels. Our findings further reveal that in both countries, mothers with lower pre-birth earnings positions face the most disadvantaged situations following separation. Based on the findings, we would like to emphasise the importance of social policies that promote female economic autonomy throughout the life course, while avoiding cuts in welfare support that risk undermining mothers’ economic safety net, as these would disproportionately affect single-headed families in lower earnings positions.