The synthesis of nano-fibrillar boehmite through electrolysis with a sacrificial aluminum anode in the presence of 0.1 mol/L sulfate electrolyte solutions at initial pH 9 and at 60 °C was carried out. The beneficial use of ammonium salt has allowed maintaining pH at a level compatible for the exclusive formation of boehmite during electrolysis from aluminate solutions. According to the experimental results and analyses inferred from X-ray diffraction pattern (XRD), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) characterizations, the mechanism of synthesis was described.