A process for preparing an oxidative dehydrogenation catalyst or oxidative dehydrogenation catalyst precursor that includes mixing solutions of molybdenum and tellurium at a pH from about 3.3 to 7.5; adjusting the pH of the resulting solution back to about 5 and adding VOSO4 and adding a solution of Nb2O5 and oxalic acid and treating the resulting precursor slurry in a controlled pressure hydrothermal process to obtain the catalyst.