Reaction of Na2WO4 and (CH3)(2)SnCl2 in water ( pH 7) led to the formation of the hybrid organic-inorganic polyanion [{(CH3)(2)Sn}(2)( W6O22)](4-)(1), which is composed of a novel hexatungstate core stabilized by two dimethyltin groups. Selective crystallization of 1 with guanidinium cations resulted in [C(NH2)(3)](4)[{(CH3)(2)Sn}(2)( (W6O22)]center dot 2H(2)O (1a), which exhibits a 1D arrangement via distorted trigonal-bipyramidal cis-(CH3)(2)SnO3 moieties.