Using a life-course perspective, we analyse the past trajectories and situations of migrants from Southern Europe who came as guest-workers in Switzerland during their adult life and who now are retired. We focus on past migratory, citizenship status and professional trajectories. We analyse how these variables influence the economic, social and health situations of migrants during the transition to retirement and after retirement. We compare their trajectories and situations with those of the Swiss-born population of the same ages. We compare also between immigrants who acquired Swiss nationality and those who are still foreigners. The concept of path dependency that leads to a process of cumulative advantages or disadvantages across the life course is particularly useful to understand the trajectories and situations of retired immigrants.