This chapter considers the mobility patterns of Barcelona dock workers of the 1940s. Labor mobility, temporary migration, the establishment of residency, and pluriactivity characterized the formation of the workforce of the Barcelona docks during the first part of the twentieth century. This chapter establishes the relationship between migration and pluriactivity, and discusses the process of transformation of mobility and migratory movements, which were initially temporary but became permanent, mainly because of economic crises. The analysis centers on three places of origin that are representative of the main socioeconomic characteristics of the Barcelona dock worker immigrants: Torrevieja (Alicante), a coastal sea town; Puebla de Arenoso (Castellón), an agricultural inland town; and Mazarrón (Murcia), a town combining mining, agriculture, and maritime activities. The sources, composed mainly of municipal registers and the personnel files of the dock workers, are analyzed using the methodology of historical record linkage.