In the historical debate, the gender wage gap is usually attributed either to productivity differences or to gender discrimination. By analysing a newly constructed series of spinning wages in the seventeenth-century Dutch Republic, the wages of male and female textile workers for the same work could be investigated. At first sight, the evidence on equal piece rates for spinning men and women seems to rule out wage discrimination. Nevertheless, more deeply rooted gender discrimination resulting from the segmented seventeenth-century labour market restricted women’s access to many professions. Exactly this segmentation determined differences in wage earning capacities between men and women.