This article makes use of linkage of many different sources – official population censuses, wage books, interviews, the correspondence of many canning companies, notarial records, documents from canning unions – in order to investigate labour market segmentation between 1880 and 1960 in the Spanish fish-canning industry, a sector that employed mainly female labour. I explore some social and economic factors that explain why women were placed in the ‘secondary’ segment of the labour market in the fish-canning sector. The study also considers the earning differentials between men and women and the different types of contracts offered to male and female workers.