Currently, there is not a general method such that any given geometry can generate a mesh with elements of hexahedral type. However, there are several methods used to create the numerical discretization for certain types of geometries. Unfortunately, these methods could generate meshes with highly distorted elements and in some cases the mesh obtained may include tangled elements. Therefore, it is of most importance to develop a procedure that could smooth and untangle hexahedral meshes. This work will provide a method that improves the quality of unstructured meshes and, if required, untangle the inverted elements by the minimization of a smoothed objective function. This objective function is based on the shape quality index of the elements or in the conditioning number of the shape matrix. To illustrate the applica- tion of the proposed smoother, several example of tangled meshes are presented, show-ing how the smoother untangles and smoothes quadrilateral and hexahedral meshes. A comparison of the performance between several minimization methods is presented. Finally, the robustness of smoother is compared to one of the most used smoothing methods.