The electrodeposition of three different heteropolyoxometalates: (HPOM) (NH4)(3)[RhMo6O18(OH)(6)].7 H2O, HPOM (1), Cu(II)(NH4)[RhMo6O18(OH)(6)].7 H2O, HPOM (2) and Cu(II) NH4 [CoMo6O18(OH)(6)].7 H2O HPOM (3) was studied by in situ atomic force microscopy (AFM) and cyclic voltammetry. It was found that the voltammetric response of compounds 2 and 3 show the deposition of the copper countercation as well as the simultaneous reduction of the corresponding heteropolyanion (HPA). AFM was used to monitor the in situ film formation of the electroreduced species on the working electrode surface. The AFM images show important differences in the film texture when copper is present in the complex.