Water adsorption on the V2O5(001) surface has been studied using density functional theory including van der Waals interactions (London dispersion interactions). Results reveal that molecular adsorption takes place via the oxygen atom bound to a naked vanadium atom. Water dimer and tetramer formed are stable adsorption configurations. The energy gap between the valence and conduction bands is not strongly correlated with the amount of adsorbed water. Such results are of great importance to test the potential use of the V2O5(001) surface as sensor for hazardous molecules in atmospheric conditions and in catalysis.