Novel complexes of trivalent Americium with hexaoxoperiodate have been prepared for the first time from an aqueous caustic solution. Chemical analysis indicated that the composition of the complexes is M I 2 [Am(OH) 2 H 2 IO 6 ]. xH 2 O (M I = alkali metal: x = 4, M I = Na, K; X = 11, M I = Li) and all the complexes have been characterised by X-ray powder diffraction, UV-Visible, IR, and Raman spectroscopic studies, and by thermal analysis.