This paper investigates internal migration decisions in Mexico. It analyses, first, the associations between migration decisions and pre-migration individual characteristics, testing the hypothesis of positive selection; second, whether and how the characteristics of the place of origin affect migration decisions; and third, whether the relationship between place characteristics and migration decisions varies depending on individual traits. Results indicate positive selection of emigrants in terms of both quantity and quality of human capital; and an important role of origin characteristics, consistent with migration transition theory.