Illegal settlements in Latin America go through various stages, both from a social, territorial, legal and urban planning point of view. Once the land has been taken or occupied, the guiding objective is usually legalisation of the land. This work looks at the case of the Saint-Martin neighbourhood (Mendoza, Argenti-na) as a paradigmatic example of the way in which the processes of approximating and legalising the land acquire, and the direct reper-cusion of that process in the city’s growth. In addition, emphasis is placed on the organisation of the population of scarce resources for housing, infrastructure and basic services.