Some mechanical characteristics of concrete and mortar reinforced with banana fibers (Musa Paradisiaca) were studied, compared with specimens added with polypropylene fibers, which were dosed at 0.5% and 1.5% in relation to the weight of the cement and in lengths of 2 cm and 4 cm. For the characterization of the fibers, water absorption tests were carried out, as well as micrographs in the scanning electron microscope, the fine and coarse aggregates were characterized by a granulometric analysis and density and absorption tests. To evaluate the performance of the concrete, compression tests, indirect stress and average residual stress were carried out, while for mortar only compression and bending tests were carried out. The results show that the banana fiber in low percentages and long lengths increases the resistance to the indirect tension of the concrete and to the bending in the mortar, surpassing in some cases the batches with polypropylene fibers.