The reaction of the epsilon-Keggin polyoxometalate (POM) [PMo12O36(OH)(4){La(H2O)(4)}(4)](5+) with Fe-II(CN)(6)(4-) under typical bench conditions at room temperature and ambient pressure has afforded the novel [epsilon-PMo12O37(OH)(3){La(H2O)(5)(Fe(CN)(6))(0.25)}(4)] network, which exhibits a three-dimensional multilayered structure. The compound has been fully characterized by synchrotron-radiation X-ray crystallography, IR spectroscopy, elemental analysis, and thermogravimetric analysis. This coordination network constitutes the first example of a cyanometalate bonded to a POM unit.