In many West African societies, labour migration has become a part of life for teenage girls. A traditional practice for boys, it has more recently caught on among young women, and is becoming a driver of sociodemographic change in rural communities. This article analyses the similarities and differences between girls’ and boys’ labour migration in a rural population of Mali. It draws upon longitudinal event history data to retrace the history of migration over a 50-year period (1960-2009) and to study its determinants, taking account of the socioeconomic context and of family rationales. Three main periods are defined, in terms of migration timing, family strategies and gender relations: a first period (1960-1979) marked by the rise of boys’ migration undertaken mainly to support the family; a second (1980-1989) marked by the rapid rise of adolescent girls’ mobility, and a third (1990-2009), marked by a weakening of the convergence between the sexes. Our analyses reveal the dynamics of the phenomenon and the influence of girls’ migration behaviour on contemporary male migration in a context where male mobility no longer necessarily takes precedence within the family.