International audienceThe paper seeks to identify the demographic trends, especially mobility, of the growth of small towns in a South Eastern Mexico region (Tehuantepec). The urbanization processes observed are characterized by the limited resources available, not only in term of services but also with regard to employment or provision of housing. However, the four urbanization patterns observed in this paper play a bridging role: between two chapters in migration stories, between productive rural area and urban employment market. It is in this way, by settlement far from the center, at the edge of small rural towns, that families look for a compromise between the declining family farming and rural economies and the difficulty in accessing...