A new molybdomanganate based on the Waugh-type polyoxoanion K1,5(NH4)4,5[MnMo9O32]·4.2H2O (1) has been synthesized in aqueous solution and characterized by single crystal X-ray diffraction, IR spectroscopy, thermogravimetric analysis and cyclic voltammetry measurements. The title compound was crystallized in the trigonal system, space group R3 with a = 15.950 (3) Å, b = 15.950 (3) Å, c = 12.447 (2) Å, γ = 120°, V = 2742.3 (9) Å3, Z = 3, R1 = 0.031 and wR2 = 0.088. Left-handed and right-handed [MnMo9O32]6− polyanions enantiomers can be observed in compound (1). The homochiral enantiomers are consolidated by many hydrogen bonds involving ammonium cations and water molecules which are stacked into a 3D framework.