We synthesized and structurally characterized the first cyanoaurate-based organotin polymer Me3Sn[Au(CN)(2)] (1), which exhibits unusual ion-exchange properties. In the structure of 1, the void space of the 2D grids formed via Au center dot center dot center dot Au bonding is filled by arrays of zigzag chains joined by weak Au center dot center dot center dot Au interactions. Interestingly, the practically insoluble polymer I shows unusual ion-exchange properties. The polymer Me2Sn[Au(CN)(2)](2) (2) was obtained in the metathesis reaction of 1 with Me2SnCl2. Compound 2 displays cyanide-bridged uninodal four-connected 3D nets with 6(5).8 topology corresponding to the CdSO4 prototype. Interestingly, 2 can be converted back into 1 by metathesis with Me3SnCl. Moreover, we performed a series of metal.-exchange experiments in which I was soaked in aqueous solutions of bivalent transition-meta[ cations M2+ (M = Co, Ni, Cu, Zn). As a result, 1 was completely converted into transition-metal cyanoaurates. To our knowledge, this represents the first study revealing the metal-exchange properties of a cyanoaurate-based heterometallic polymer.