The availability of childcare is a crucial factor for mothers’ labour force participation. While most of the literature examines childcare for preschool children, we specifically focus on primary school-aged children, estimating the effect of formal afternoon care on maternal labour supply. To do so, we use a novel matching technique, entropy balancing, and draw on the rich and longitudinal data of the German Socio-Economic Panel (SOEP). We show that children’s afternoon care increases mothers’ employment rates and their working hours. To confirm the robustness of our results, we conduct a series of sensitivity analyses and apply a newly proposed method to assess possible bias from omitted variables. Our findings highlight how childcare availability shapes maternal employment patterns well after school entry.