A convenient method for the systematic introduction of a variety of organoimido ligands at terminal oxo sites in the hexamolybdate cluster [Bu4N](2)[Mo6O19] is described, consisting of reaction with the appropriate organic isocyanate RNCO (R = n-butyl, cyclohexyl, 2,6-diisopropylphenyl) in pyridine solution. Singly functionalized imido-hexamolybdates [Mo6O18(NR)](2-) incorporating each of the above substituents are described. In the case of the 2,6-(diisopropyl)phenylimido ligand (NAr), multiple functionalization has also been achieved: hexamolybdate derivatives [Mo6O(19-x)(NAr)(x)](2-) incorporating two, three, four, and five NAr ligands at terminal sites have been prepared. The complexes have been characterized by cyclic voltammetry, multinuclear (H-1,N-14,O-17, and Mo-95) NMR and electronic spectroscopy, and single-crystal X-ray diffraction studies.