Steel-Concrete composite beam-columns are formed by the association of a steel profile with concrete, taking best advantage of each material characteristic. In this paper the behavior of composite steel-concrete beam columns, with emphasis on tubular concrete filled sections, is investigated by the finite element method. Different one-dimensional element formulations are considered, e.g. cubic interpolation and corotational elements. The implementation allows the consideration of initial lack of straightness of the column, of different stress strain relations (by exact integration of the stiffness at the section level), as well as the physical and geometrical non-linearities involved in the problem. Comparisons with experimental data are presented at the end of the paper. The developed numerical formulation is able to predict accurately the behavior of slender concrete filled tubes under static loading.