A process for preparing a catalyst for maleic anhydride production wherein a null5 vanadium compound such as V2O5, an anhydrous phosphoric acid, and optionally promoters are admixed in an organic alcohol solvent, the admixture is rapidly brought to reflux and thereafter refluxed to reduced the vanadium compound to the desired degree, the reflux mixture is cooled, precursor crystals are separated by filtration and then dried and calcined.