Cross-border working is a phenomenon that has concerned a growing number of people in Europe since the beginning of the 2000s. Lorraine, which constitutes a large labour pool and until the recent territorial reform was the only French region with borders with three countries, is concerned by large-scale flows into Luxembourg and to a lesser extent into Germany, and therefore represents a pertinent area to study to identify the geographical and economic dimensions of cross-border working. Cross-border working is analysed as a factor in regulating the job market through its heterogeneity, but also the legal standardisation of the status of the cross-border worker.