ABSTRACT: Dry-stacked post-tensioned masonry has many technical and economic advantages when used as a construction method for outside walls of buildings exposed to wind and seismic loads. Other important applications for this method include: walls loaded in their plane to resist seismic forces, beams and slabs. The use of dry-stacked masonry in engineering practice requires structural calculation methods for these structural elements so that the capacity to withstand the loads to which the walls are subjected, and good behavior in the elastic range can be guaranteed. Existing methods use the concept of flexural rigidity, EI, with a constant elastic modulus, E, which is applicable only in a very limited range of the behavior of structural elements, beams, walls or slabs. In addition, the effective inertia, I, is uncertain and variable after the elastic range is exceeded. This paper shows the results of a methodology based on moment-curvature relationships to predict the behavior of dry-stacked post-tensioned masonry beams. Stress-strain relationships of both the masonry and post-tensioning cables, in addition to the geometry of masonry units, are required to build moment-curvature relationships, there bye liminating the need of the modulus of elasticity. The prediction made by this method shows a good fit with the behavior of the beams tested in the laboratory, and could also have a wide application to reinforced and post-tensioned concrete elements.