For several decades the architecture of the Modern Movement has acquired a new value as new element in our culturalheritage in its condition of relevant testimony for the society and culture of 20th century. From the emergenceof the postmodern era at the end of the sixties’s decade in the last century, the Modern Movement reaches the conditionof historically and, bathed in a kind of glory, begins to be longed for many contemporary architects. From thisfascination there will arise the diverse attempts of reconstructions of key dissapeared masterpieces, phenomenonreinforced by the simultaneous restoration of paradigmatic buildings as the house of Rietveld in Utrecht, the MaisonDouble by Le Corbusier or the Villa of Adolf Loos’s Dr. Müller in Prague.This topic practically ignored in the contemporary historiography, is approached in this essay from a triple perspective:first, the unavoidable summary of the sources and studies published on the conservation and restoration of thearchitecture of the Modern Movement; secondly, the discussion around the criteria of restoration that is the contextwhere could be understood the phenomenon of the reconstruction of missing Works and, concluding, the detailedanálisis of the most significant cases, with special atention to those realized in Spain.