The hypothesis in this research consists in that, the free trade treaties will have differential effects in the productive structure, the foreign trade and the investments in each region, it depends on its competition expressed in the opening degree and transaction of the regional economy, its sector specialization, the Geographic destination of exports and the competitive countries of its substitute sector of imports, and its urban and infrastructure advantages. This research demonstrates that the regional effects of NAFTA and Mercosur in Chile will be promising for some regions and it will be injurious for others. Eight regions-most with these treaties, meanwhile, other four in the south and central south won’t receive benefits likewise. Mercosur, supporting, mainly, the exporter industrial district- which is located mostly in the metropolitan region but Mercosur, at the same time, prejudices the regions with traditional agrarian economy, it would have a concentrating territorial effect. NAFTA, on the other hand, is generally more profitable for non-metropolitan regions with economies which are based on the natural resources area and on its processing industry. It’s recommended, consequently, a reformulation of new regional strategies of development-which generally don’t consider the setting NAFTA-Mercosur-oriented to capitalize the opportunities of treaties, likewise, to reconvert these less competitive sectors and regions in an anticipated and progressive way.