In this study, a computational code has been developed based into Finite Elements Method in the version of LSFEM (Least Squares Finite Element Method). The numeric development of this method has as a main advantage, the obtaining of an always symmetrical and defined positive algebraic system, independently of the considered partial-differential equation system. The computational code was applied in the solution of two-dimensional and three-dimensional convection-diffusion problems, through domain discretization of structured meshes of quadratic elements. Obtained numerical results showed a good concordance with available results, showing the developed model validity Ver menos