Two new organometallic-inorganic charge transfer salts formulated as [(η5-Cp)Fe(η6-MeO-p-C6H 4-NHNH2)]2[Mo6O19], 1, and [(η5-Cp)Fe(η6-MeO-p-C6H 4-NHNH2)]4[β-Mo8O 26], 2, were prepared through a metathesis reaction between the organometallic hydrazine precursor [(η5-Cp)Fe(η6- MeO-p-C6H4-NHNH2)]+PF 6- and either [n-Bu4N]2[Mo 6O19] or [n-Bu4N]4[α-Mo 8O26] in acetonitrile. In the second case, the [α-Mo8O26]4- anion transforms into the [β-Mo8O26]4- isomer. These organometallic-inorganic hybrids were characterized by spectroscopic techniques (IR, 1H NMR and UV-vis). In addition, the UV-vis diffuse reflectance spectra of 1 and 2 in solid state exhibit a band at λmax = 475 and 470 nm, respectively, not observed in DMSO solution, which have been attributed to a charge transfer transition. On the other hand, the solid state structure of 2, solved by X-ray diffraction analysis shows the formation of hydrogen bonds between the protons of the -NHNH2 and C-H groups with the terminal oxo groups of the β-octamolybdate anions [β-Mo 8O26]4-. Finally, hybrid 3, formulated as [(η5-Cp)Fe(η6-C6H5OMe)] 4[β-Mo8O26] was prepared in EtOH under solvothermal conditions. The single crystal X-ray structure shows the elimination of the -NHNH2 group from the organometallic mixed sandwich reducing its associative ability toward the oxo groups of the counterion only to the electrostatic interactions and to the very weak CH⋯O hydrogen bonds.