Among the many actions undertaken by the Compañía de Jesús in America, the experience of the missions of Guaraníes is something remarkable. What the Jesuit carried out in the "Paraguay" can appear to be something positive as well as something negative. But what truly makes the Guaraníes missions an unprecedented experience is the complete set of situations of everyday life and total organizational sense of each part of the mission, set between missionaries, population and the territory. Although we could find antecedents in the Guaraní and Peruvian regions, there are authors who make comparisons with European theories like those of Plato, Saint Agustine, Thomas Moro and Campanella. After some general words about the project the paper continues, describing how in each new enterprise the earlier experiences ruled, developing a pragmatic evolution. The physical planning was accompanied by a general vision of social, cultural, political and economic aspects within a wide religious frame. This frame leaned not only on the vision that the missionary brought from Europe with his beliefs and culture, but that also on the visions on the world and its relation with the natural and the supernatural locally found. The article reviews aspects of geographic environment, bases and antecedents of the project, the general territory, urbanism, Guaraní culture, arts and crafts, social and political organization of the missions, economy and the systems of evangelization.