The Latin American city is more compact than the European. Their densities are higher and their peripheries less fragmented, isolated the effect of geographical support. This is explained by the stage of developing their economies and occurs in a context of continuous urban sprawl. Urban planning can not curb urban sprawl, only attenuate or amplify their effects, the main fragmentation. The dispersion pattern of urban expansion expresses a set of factors whose tendency is to maximize short-term economic, collection of land rent at the expense of long-term social adjustment.