The DL 3.516/80 allows the division of rustic properties up to 0, 5 hectares. Its application in the outskirts of Santiago has generated the urbanization of the countryside not considering the existing territorial planning instruments, which only regulate urban spaces. Santiago suffered a strong expansion until 1994 when the Metropolitan Regulation Plan of Santiago (PRMS in Spanish), fixed the urban boundary. Its appearance generated the subdivision of fields and the speculation of land, under the DL 3.516/80.This investigation studies the territorial impact of the DL 3.516/80 and its relation with the PRMS on the outskirts of Santiago, Chile. Through a bibliographic and cartographic analysis, interviews to key local agents and using GIS, the area affected by the DL 3.516/80 is determined, the quality of its soils and the area lost by agriculture due to the urbanization of the countryside, which generates the "infiltrated city".