In this work the influence of La2O3 particles addition on the crystallization of Zr55Al10Ni5Cu30 amorphous ribbons was studied. Non-doped and doped amorphous ribbons were produced by melt-spinning technique, where the doping particles were introduced in the molten alloy just before ejection. The crystallization behavior and microstructure development upon annealing have been investigated by a combination of differential scanning calorimetry (DSC), transmission electron microscopy (TEM) and X-ray diffraction (XRD). Doping of Zr55Al10Ni5CU30 amorphous ribbon with La2O3 particles does not change the undercooled liquid range indicating no influence on the glass forming ability (GFA) and oxygen content. However, doping changes the crystallization process from one stage observed for the non-doped ribbon to a two-stage process. The crystallization of the doped ribbon leads to the formation of a quasicrystalline phase. The lower activation energy for quasicrystalline phase than that for the Zr4Cu2O phase might have changed the kinetic competition between the phases and allowing the formation of the quasicrystalline phase.